Diff for /loncom/interface/loncoursedata.pm between versions 1.18 and 1.162

version 1.18, 2002/08/15 16:03:11 version 1.162, 2006/04/28 21:51:35
Line 1 Line 1
 # The LearningOnline Network with CAPA  # The LearningOnline Network with CAPA
 # (Publication Handler  
 #  #
 # $Id$  # $Id$
 #  #
Line 35  loncoursedata Line 34  loncoursedata
   
 =head1 SYNOPSIS  =head1 SYNOPSIS
   
 Set of functions that download and process student information.  Set of functions that download and process student and course information.
   
 =head1 PACKAGES USED  =head1 PACKAGES USED
   
  Apache::Constants qw(:common :http)   Apache::Constants qw(:common :http)
  Apache::lonnet()   Apache::lonnet()
    Apache::lonhtmlcommon
  HTML::TokeParser   HTML::TokeParser
  GDBM_File   GDBM_File
   
Line 49  Set of functions that download and proce Line 49  Set of functions that download and proce
 package Apache::loncoursedata;  package Apache::loncoursedata;
   
 use strict;  use strict;
 use Apache::Constants qw(:common :http);  use Apache::lonnet;
 use Apache::lonnet();  
 use Apache::lonhtmlcommon;  use Apache::lonhtmlcommon;
   use Time::HiRes;
   use Apache::lonmysql;
 use HTML::TokeParser;  use HTML::TokeParser;
 use GDBM_File;  use GDBM_File;
   
Line 59  use GDBM_File; Line 60  use GDBM_File;
   
 =head1 DOWNLOAD INFORMATION  =head1 DOWNLOAD INFORMATION
   
 This section contains all the files that get data from other servers   This section contains all the functions that get data from other servers 
 and/or itself.  There is one function that has a call to get remote  and/or itself.
 information but isn't included here which is ProcessTopLevelMap.  The  
 usage was small enough to be ignored, but that portion may be moved  
 here in the future.  
   
 =cut  =cut
   
 # ----- DOWNLOAD INFORMATION -------------------------------------------  ################################################
   ################################################
   
 =pod  =pod
   
 =item &DownloadClasslist()  =item &make_into_hash($values);
   
 Collects lastname, generation, middlename, firstname, PID, and section for each  Returns a reference to a hash as described by $values.  $values is
 student from their environment database.  The list of students is built from  assumed to be the result of 
 collecting a classlist for the course that is to be displayed.      join(':',map {&Apache::lonnet::escape($_)} %orighash);
   
 =over 4  This is a helper function for get_current_state.
   
 Input: $courseID, $c  =cut
   
 $courseID:  The id of the course  ################################################
   ################################################
   sub make_into_hash {
       my $values = shift;
       my %tmp = map { &Apache::lonnet::unescape($_); }
                                              split(':',$values);
       return \%tmp;
   }
   
 $c: The connection class that can determine if the browser has aborted.  It  
 is used to short circuit this function so that it doesn't continue to   
 get information when there is no need.  
   
 Output: \%classlist  ################################################
   ################################################
   
 \%classlist: A pointer to a hash containing the following data:  =pod
   
 -A list of student name:domain (as keys) (known below as $name)  =head1 LOCAL DATA CACHING SUBROUTINES
   
 -A hash pointer for each student containing lastname, generation, firstname,  The local caching is done using MySQL.  There is no fall-back implementation
 middlename, and PID : Key is $name.'studentInformation'  if MySQL is not running.
   
 -A hash pointer to each students section data : Key is $name.section  The programmers interface is to call &get_current_state() or some other
   primary interface subroutine (described below).  The internals of this 
   storage system are documented here.
   
 =back  There are six tables used to store student performance data (the results of
   a dumpcurrent).  Each of these tables is created in MySQL with a name of
   $courseid_*****, where ***** is 'symb', 'part', or whatever is appropriate 
   for the table.  The tables and their purposes are described below.
   
 =cut  Some notes before we get started.
   
 sub DownloadClasslist {  Each table must have a PRIMARY KEY, which is a column or set of columns which
     my ($courseID, $lastDownloadTime, $c)=@_;  will serve to uniquely identify a row of data.  NULL is not allowed!
     my ($courseDomain,$courseNumber)=split(/\_/,$courseID);  
     my %classlist;  
   
     my $modifiedTime = &GetFileTimestamp($courseDomain, $courseNumber,  
                                      'classlist.db',   
                                      $Apache::lonnet::perlvar{'lonUsersDir'});  
   
     if($lastDownloadTime ne 'Not downloaded' &&  
        $lastDownloadTime >= $modifiedTime && $modifiedTime >= 0) {  
         $classlist{'lastDownloadTime'}=time;  
         $classlist{'UpToDate'} = 'true';  
         return \%classlist;  
     }  
   
     %classlist=&Apache::lonnet::dump('classlist',$courseDomain, $courseNumber);  INDEXes work best on integer data.
     my ($checkForError)=keys (%classlist);  
     if($checkForError =~ /^(con_lost|error|no_such_host)/i) {  
         return \%classlist;  
     }  
   
     foreach my $name (keys(%classlist)) {  JOIN is used to combine data from many tables into one output.
         if($c->aborted()) {  
             $classlist{'error'}='aborted';  
             return \%classlist;  
         }  
   
         my ($studentName,$studentDomain) = split(/\:/,$name);  lonmysql.pm is used for some of the interface, specifically the table creation
         # Download student environment data, specifically the full name and id.  calls.  The inserts are done in bulk by directly calling the database handler.
         my %studentInformation=&Apache::lonnet::get('environment',  The SELECT ... JOIN statement used to retrieve the data does not have an
                                                     ['lastname','generation',  interface in lonmysql.pm and I shudder at the thought of writing one.
                                                      'firstname','middlename',  
                                                      'id'],  
                                                     $studentDomain,  
                                                     $studentName);  
         $classlist{$name.':studentInformation'}=\%studentInformation;  
   
         if($c->aborted()) {  =head3 Table Descriptions
             $classlist{'error'}='aborted';  
             return \%classlist;  
         }  
   
         #Section  =over 4
         my %section=&Apache::lonnet::dump('roles',$studentDomain,$studentName);  
         $classlist{$name.':sections'}=\%section;  
     }  
   
     $classlist{'UpToDate'} = 'false';  =item Tables used to store meta information
     $classlist{'lastDownloadTime'}=time;  
   
     return \%classlist;  The following tables hold data required to keep track of the current status
 }  of a students data in the tables or to look up the students data in the tables.
   
 =pod  =over 4
   
   =item $symb_table
   
   The symb_table has two columns.  The first is a 'symb_id' and the second
   is the text name for the 'symb' (limited to 64k).  The 'symb_id' is generated
   automatically by MySQL so inserts should be done on this table with an
   empty first element.  This table has its PRIMARY KEY on the 'symb_id'.
   
   =item $part_table
   
   The part_table has two columns.  The first is a 'part_id' and the second
   is the text name for the 'part' (limited to 100 characters).  The 'part_id' is
   generated automatically by MySQL so inserts should be done on this table with
   an empty first element.  This table has its PRIMARY KEY on the 'part' (100
   characters) and a KEY on 'part_id'.
   
   =item $student_table
   
   The student_table has 7 columns.  The first is a 'student_id' assigned by 
   MySQL.  The second is 'student' which is username:domain.  The third through
   fifth are 'section', 'status' (enrollment status), and 'classification' 
   (to be used in the future).  The sixth and seventh ('updatetime' and 
   'fullupdatetime') contain the time of last update and full update of student
   data.  This table has its PRIMARY KEY on the 'student_id' column and is indexed
   on 'student', 'section', and 'status'.
   
 =item &DownloadCourseInformation()  =back 
   
 Dump of all the course information for a single student.  There is no  =item Tables used to store current status data
 pruning of data, it is all stored in a hash and returned.  It also  
 checks the timestamp of the students course database file and only downloads  The following tables store data only about the students current status on 
 if it has been modified since the last download.  a problem, meaning only the data related to the last attempt on a problem.
   
 =over 4  =over 4
   
 Input: $name, $courseID  =item $performance_table
   
   The performance_table has 9 columns.  The first three are 'symb_id', 
   'student_id', and 'part_id'.  These comprise the PRIMARY KEY for this table
   and are directly related to the $symb_table, $student_table, and $part_table
   described above.  MySQL does better indexing on numeric items than text,
   so we use these three "index tables".  The remaining columns are
   'solved', 'tries', 'awarded', 'award', 'awarddetail', and 'timestamp'.
   These are either the MySQL type TINYTEXT or various integers ('tries' and 
   'timestamp').  This table has KEYs of 'student_id' and 'symb_id'.
   For use of this table, see the functions described below.
   
   =item $parameters_table
   
   The parameters_table holds the data that does not fit neatly into the
   performance_table.  The parameters table has four columns: 'symb_id',
   'student_id', 'parameter', and 'value'.  'symb_id', 'student_id', and
   'parameter' comprise the PRIMARY KEY for this table.  'parameter' is 
   limited to 255 characters.  'value' is limited to 64k characters.
   
   =back
   
   =item Tables used for storing historic data
   
   The following tables are used to store almost all of the transactions a student
   has made on a homework problem.  See loncapa/docs/homework/datastorage for 
   specific information about each of the parameters stored.  
   
 $name: student name:domain  =over 4
   
 $courseID:  The id of the course  =item $fulldump_response_table
   
 Output: \%courseData  The response table holds data (documented in loncapa/docs/homework/datastorage)
   associated with a particular response id which is stored when a student 
   attempts a problem.  The following are the columns of the table, in order:
   'symb_id','part_id','response_id','student_id','transaction','tries',
   'awarddetail', 'response_specific', 'response_specific_value',
   'response_specific_2', 'response_specific_value_2', and 'submission
   (the text of the students submission).  The primary key is based on the
   first five columns listed above.
   
   =item $fulldump_part_table
   
   The part table holds data (documented in loncapa/docs/homework/datastorage)
   associated with a particular part id which is stored when a student attempts
   a problem.  The following are the columns of the table, in order:
   'symb_id','part_id','student_id','transaction','tries','award','awarded',
   and 'previous'.  The primary key is based on the first five columns listed 
   above.
   
   =item $fulldump_timestamp_table
   
   The timestamp table holds the timestamps of the transactions which are
   stored in $fulldump_response_table and $fulldump_part_table.  This data is
   about both the response and part data.  Columns: 'symb_id','student_id',
   'transaction', and 'timestamp'.  
   The primary key is based on the first 3 columns.
   
   =item $weight_table
   
   The weight table holds the weight for the problems used in the class.
   Whereas the weight of a problem can vary by section and student the data
   here is applied to the class as a whole.
   Columns: 'symb_id','part_id','response_id','weight'.
   
 \%courseData:  A hash pointer to the raw data from the student's course  =back
 database.  
   
 =back  =back
   
   =head3 Important Subroutines
   
   Here is a brief overview of the subroutines which are likely to be of 
   interest:
   
   =over 4
   
   =item &get_current_state(): programmers interface.
   
   =item &init_dbs(): table creation
   
   =item &update_student_data(): data storage calls
   
   =item &get_student_data_from_performance_cache(): data retrieval
   
   =back
   
   =head3 Main Documentation
   
   =over 4
   
 =cut  =cut
   
 sub DownloadCourseInformation {  ################################################
     my ($namedata,$courseID,$lastDownloadTime,$WhatIWant)=@_;  ################################################
     my %courseData;  
     my ($name,$domain) = split(/\:/,$namedata);  
   
     my $modifiedTime = &GetFileTimestamp($domain, $name,  ################################################
                                       $courseID.'.db',   ################################################
                                       $Apache::lonnet::perlvar{'lonUsersDir'});  { # Begin scope of table identifiers
   
   my $current_course ='';
   my $symb_table;
   my $part_table;
   my $student_table;
   my $performance_table;
   my $parameters_table;
   my $fulldump_response_table;
   my $fulldump_part_table;
   my $fulldump_timestamp_table;
   my $weight_table;
   
   my @Tables;
   ################################################
   ################################################
   
     if($lastDownloadTime >= $modifiedTime && $modifiedTime >= 0) {  =pod
         $courseData{$namedata.':lastDownloadTime'}=time;  
         $courseData{$namedata.':UpToDate'} = 'true';  
         return \%courseData;  
     }  
   
     # Download course data  =item &init_dbs()
     if(!defined($WhatIWant)) {  
         $WhatIWant = '.';  
     }  
     %courseData=&Apache::lonnet::dump($courseID, $domain, $name, $WhatIWant);  
     $courseData{'UpToDate'} = 'false';  
     $courseData{'lastDownloadTime'}=time;  
   
     my %newData;  Input: course id
     foreach (keys(%courseData)) {  
         $newData{$namedata.':'.$_} = $courseData{$_};  Output: 0 on success, positive integer on error
     }  
   This routine issues the calls to lonmysql to create the tables used to
   store student data.
   
   =cut
   
     return \%newData;  ################################################
   ################################################
   sub init_dbs {
       my ($courseid,$drop) = @_;
       &setup_table_names($courseid);
       #
       # Drop any of the existing tables
       if ($drop) {
           foreach my $table (@Tables) {
               &Apache::lonmysql::drop_table($table);
           }
       }
       #
       # Note - changes to this table must be reflected in the code that 
       # stores the data (calls &Apache::lonmysql::store_row with this table
       # id
       my $symb_table_def = {
           id => $symb_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'symb',
                         type => 'MEDIUMTEXT',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['symb_id'],
       };
       #
       my $part_table_def = {
           id => $part_table,
           permanent => 'no',
           columns => [{ name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'part',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL'},
                       ],
           'PRIMARY KEY' => ['part (100)'],
           'KEY' => [{ columns => ['part_id']},],
       };
       #
       my $student_table_def = {
           id => $student_table,
           permanent => 'no',
           columns => [{ name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL',
                         auto_inc     => 'yes', },
                       { name => 'student',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL UNIQUE'},
                       { name => 'section',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL'},
                       { name => 'status',
                         type => 'VARCHAR(15) BINARY',
                         restrictions => 'NOT NULL'},
                       { name => 'classification',
                         type => 'VARCHAR(100) BINARY', },
                       { name => 'updatetime',
                         type => 'INT UNSIGNED'},
                       { name => 'fullupdatetime',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['student_id'],
           'KEY' => [{ columns => ['student (100)',
                                   'section (100)',
                                   'status (15)',]},],
       };
       #
       my $performance_table_def = {
           id => $performance_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'part',
                         type => 'VARCHAR(100) BINARY',
                         restrictions => 'NOT NULL'},                    
                       { name => 'solved',
                         type => 'TINYTEXT' },
                       { name => 'tries',
                         type => 'SMALLINT UNSIGNED' },
                       { name => 'awarded',
                         type => 'REAL' },
                       { name => 'award',
                         type => 'TINYTEXT' },
                       { name => 'awarddetail',
                         type => 'TINYTEXT' },
                       { name => 'timestamp',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','part_id'],
           'KEY' => [{ columns=>['student_id'] },
                     { columns=>['symb_id'] },],
       };
       #
       my $fulldump_part_table_def = {
           id => $fulldump_part_table,
           permanent => 'no',
           columns => [
                       { name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'transaction',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'tries',
                         type => 'SMALLINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'award',
                         type => 'TINYTEXT' },
                       { name => 'awarded',
                         type => 'REAL' },
                       { name => 'previous',
                         type => 'SMALLINT UNSIGNED' },
   #                    { name => 'regrader',
   #                      type => 'TINYTEXT' },
   #                    { name => 'afterduedate',
   #                      type => 'TINYTEXT' },
                       ],
           'PRIMARY KEY' => ['symb_id','part_id','student_id','transaction'],
           'KEY' => [
                     { columns=>['symb_id'] },
                     { columns=>['part_id'] },
                     { columns=>['student_id'] },
                     ],
       };
       #
       my $fulldump_response_table_def = {
           id => $fulldump_response_table,
           permanent => 'no',
           columns => [
                       { name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'response_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'transaction',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'awarddetail',
                         type => 'TINYTEXT' },
   #                    { name => 'message',
   #                      type => 'CHAR BINARY'},
                       { name => 'response_specific',
                         type => 'TINYTEXT' },
                       { name => 'response_specific_value',
                         type => 'TINYTEXT' },
                       { name => 'response_specific_2',
                         type => 'TINYTEXT' },
                       { name => 'response_specific_value_2',
                         type => 'TINYTEXT' },
                       { name => 'submission',
                         type => 'TEXT'},
                       ],
               'PRIMARY KEY' => ['symb_id','part_id','response_id','student_id',
                                 'transaction'],
               'KEY' => [
                         { columns=>['symb_id'] },
                         { columns=>['part_id','response_id'] },
                         { columns=>['student_id'] },
                         ],
       };
       my $fulldump_timestamp_table_def = {
           id => $fulldump_timestamp_table,
           permanent => 'no',
           columns => [
                       { name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'transaction',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL' },
                       { name => 'timestamp',
                         type => 'INT UNSIGNED'},
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','transaction'],
           'KEY' => [
                     { columns=>['symb_id'] },
                     { columns=>['student_id'] },
                     { columns=>['transaction'] },
                     ],
       };
       #
       my $parameters_table_def = {
           id => $parameters_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'student_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'parameter',
                         type => 'TINYTEXT',
                         restrictions => 'NOT NULL'  },
                       { name => 'value',
                         type => 'MEDIUMTEXT' },
                       ],
           'PRIMARY KEY' => ['symb_id','student_id','parameter (255)'],
       };
       #
       my $weight_table_def = {
           id => $weight_table,
           permanent => 'no',
           columns => [{ name => 'symb_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'part_id',
                         type => 'MEDIUMINT UNSIGNED',
                         restrictions => 'NOT NULL'  },
                       { name => 'weight',
                         type => 'REAL',
                         restrictions => 'NOT NULL'  },
                       ],
           'PRIMARY KEY' => ['symb_id','part_id'],
       };
       #
       # Create the tables
       my $tableid;
       $tableid = &Apache::lonmysql::create_table($symb_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating symb_table: ".
                                    &Apache::lonmysql::get_error());
           return 1;
       }
       #
       $tableid = &Apache::lonmysql::create_table($part_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating part_table: ".
                                    &Apache::lonmysql::get_error());
           return 2;
       }
       #
       $tableid = &Apache::lonmysql::create_table($student_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating student_table: ".
                                    &Apache::lonmysql::get_error());
           return 3;
       }
       #
       $tableid = &Apache::lonmysql::create_table($performance_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating preformance_table: ".
                                    &Apache::lonmysql::get_error());
           return 5;
       }
       #
       $tableid = &Apache::lonmysql::create_table($parameters_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating parameters_table: ".
                                    &Apache::lonmysql::get_error());
           return 6;
       }
       #
       $tableid = &Apache::lonmysql::create_table($fulldump_part_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating fulldump_part_table: ".
                                    &Apache::lonmysql::get_error());
           return 7;
       }
       #
       $tableid = &Apache::lonmysql::create_table($fulldump_response_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating fulldump_response_table: ".
                                    &Apache::lonmysql::get_error());
           return 8;
       }
       $tableid = &Apache::lonmysql::create_table($fulldump_timestamp_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating fulldump_timestamp_table: ".
                                    &Apache::lonmysql::get_error());
           return 9;
       }
       $tableid = &Apache::lonmysql::create_table($weight_table_def);
       if (! defined($tableid)) {
           &Apache::lonnet::logthis("error creating weight_table: ".
                                    &Apache::lonmysql::get_error());
           return 10;
       }
       return 0;
 }  }
   
 # ----- END DOWNLOAD INFORMATION ---------------------------------------  ################################################
   ################################################
   
 =pod  =pod
   
 =head1 PROCESSING FUNCTIONS  =item &delete_caches()
   
   This routine drops all the tables associated with a course from the 
   MySQL database.
   
   Input: course id (optional, determined by environment if omitted) 
   
 These functions process all the data for all the students.  Also, they  Returns: nothing
 are the only functions that access the cache database for writing.  Thus  
 they are the only functions that cache data.  The downloading and caching  
 were separated to reduce problems with stopping downloading then can't  
 tie hash to database later.  
   
 =cut  =cut
   
 # ----- PROCESSING FUNCTIONS ---------------------------------------  ################################################
   ################################################
   sub delete_caches {
       my $courseid = shift;
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       foreach my $table (@Tables) {
           my $command = 'DROP TABLE '.$table.';';
           $dbh->do($command);
           if ($dbh->err) {
               &Apache::lonnet::logthis($command.' resulted in error: '.$dbh->errstr);
           }
       }
       return;
   }
   
   ################################################
   ################################################
   
 =pod  =pod
   
 =item &ProcessTopResourceMap()  =item &get_part_id()
   
 Trace through the "big hash" created in rat/lonuserstate.pm::loadmap.    Get the MySQL id of a problem part string.
 Basically, this function organizes a subset of the data and stores it in  
 cached data.  The data stored is the problems, sequences, sequence titles,  
 parts of problems, and their ordering.  Column width information is also   
 partially handled here on a per sequence basis.  
   
 =over 4  Input: $part
   
 Input: $cache, $c  Output: undef on error, integer $part_id on success.
   
 $cache:  A pointer to a hash to store the information  =item &get_part()
   
 $c:  The connection class used to determine if an abort has been sent to the   Get the string describing a part from the MySQL id of the problem part.
 browser  
   
 Output: A string that contains an error message or "OK" if everything went   Input: $part_id
 smoothly.  
   
 =back  Output: undef on error, $part string on success.
   
 =cut  =cut
   
 sub ProcessTopResourceMap {  ################################################
     my ($cache,$c)=@_;  ################################################
     my %hash;  
     my $fn=$ENV{'request.course.fn'};  my $have_read_part_table = 0;
     if(-e "$fn.db") {  my %ids_by_part;
  my $tieTries=0;  my %parts_by_id;
  while($tieTries < 3) {  
             if($c->aborted()) {  sub get_part_id {
                 return;      my ($part) = @_;
             }      $part = 0 if (! defined($part));
     if(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {      if (! $have_read_part_table) {
  last;          my @Result = &Apache::lonmysql::get_rows($part_table);
     }          foreach (@Result) {
     $tieTries++;              $ids_by_part{$_->[1]}=$_->[0];
     sleep 1;          }
  }          $have_read_part_table = 1;
  if($tieTries >= 3) {      }
             return 'Coursemap undefined.';      if (! exists($ids_by_part{$part})) {
           &Apache::lonmysql::store_row($part_table,[undef,$part]);
           undef(%ids_by_part);
           my @Result = &Apache::lonmysql::get_rows($part_table);
           foreach (@Result) {
               $ids_by_part{$_->[1]}=$_->[0];
         }          }
     } else {  
         return 'Can not open Coursemap.';  
     }      }
       return $ids_by_part{$part} if (exists($ids_by_part{$part}));
       return undef; # error
   }
   
     # Initialize state machine.  Set information pointing to top level map.  sub get_part {
     my (@sequences, @currentResource, @finishResource);      my ($part_id) = @_;
     my ($currentSequence, $currentResourceID, $lastResourceID);      if (! exists($parts_by_id{$part_id})  || 
           ! defined($parts_by_id{$part_id}) ||
     $currentResourceID=$hash{'ids_/res/'.$ENV{'request.course.uri'}};          $parts_by_id{$part_id} eq '') {
     push(@currentResource, $currentResourceID);          my @Result = &Apache::lonmysql::get_rows($part_table);
     $lastResourceID=-1;          foreach (@Result) {
     $currentSequence=-1;              $parts_by_id{$_->[0]}=$_->[1];
     my $topLevelSequenceNumber = $currentSequence;          }
       }
     my %sequenceRecord;      return $parts_by_id{$part_id} if(exists($parts_by_id{$part_id}));
     while(1) {      return undef; # error
         if($c->aborted()) {  }
             last;  
         }  
  # HANDLE NEW SEQUENCE!  
  #if page || sequence  
  if(defined($hash{'map_pc_'.$hash{'src_'.$currentResourceID}}) &&  
            !defined($sequenceRecord{$currentResourceID})) {  
             $sequenceRecord{$currentResourceID}++;  
     push(@sequences, $currentSequence);  
     push(@currentResource, $currentResourceID);  
     push(@finishResource, $lastResourceID);  
   
     $currentSequence=$hash{'map_pc_'.$hash{'src_'.$currentResourceID}};  
   
             # Mark sequence as containing problems.  If it doesn't, then  
             # it will be removed when processing for this sequence is  
             # complete.  This allows the problems in a sequence  
             # to be outputed before problems in the subsequences  
             if(!defined($cache->{'orderedSequences'})) {  
                 $cache->{'orderedSequences'}=$currentSequence;  
             } else {  
                 $cache->{'orderedSequences'}.=':'.$currentSequence;  
             }  
   
     $lastResourceID=$hash{'map_finish_'.  ################################################
   $hash{'src_'.$currentResourceID}};  ################################################
     $currentResourceID=$hash{'map_start_'.  
      $hash{'src_'.$currentResourceID}};  
   
     if(!($currentResourceID) || !($lastResourceID)) {  
  $currentSequence=pop(@sequences);  
  $currentResourceID=pop(@currentResource);  
  $lastResourceID=pop(@finishResource);  
  if($currentSequence eq $topLevelSequenceNumber) {  
     last;  
  }  
     }  
             next;  
  }  
   
  # Handle gradable resources: exams, problems, etc  =pod
  $currentResourceID=~/(\d+)\.(\d+)/;  
         my $partA=$1;  
         my $partB=$2;  
  if($hash{'src_'.$currentResourceID}=~  
    /\.(problem|exam|quiz|assess|survey|form)$/ &&  
    $partA eq $currentSequence &&   
            !defined($sequenceRecord{$currentSequence.':'.  
                                     $currentResourceID})) {  
             $sequenceRecord{$currentSequence.':'.$currentResourceID}++;  
     my $Problem = &Apache::lonnet::symbclean(  
   &Apache::lonnet::declutter($hash{'map_id_'.$partA}).  
   '___'.$partB.'___'.  
   &Apache::lonnet::declutter($hash{'src_'.  
  $currentResourceID}));  
   
     $cache->{$currentResourceID.':problem'}=$Problem;  
     if(!defined($cache->{$currentSequence.':problems'})) {  
  $cache->{$currentSequence.':problems'}=$currentResourceID;  
     } else {  
  $cache->{$currentSequence.':problems'}.=  
     ':'.$currentResourceID;  
     }  
   
     my $meta=$hash{'src_'.$currentResourceID};  =item &get_symb_id()
 #            $cache->{$currentResourceID.':title'}=  
 #                &Apache::lonnet::metdata($meta,'title');  
             $cache->{$currentResourceID.':title'}=  
                 $hash{'title_'.$currentResourceID};  
             $cache->{$currentResourceID.':source'}=  
                 $hash{'src_'.$currentResourceID};  
   
             # Get Parts for problem  
             my %beenHere;  
             foreach (split(/\,/,&Apache::lonnet::metadata($meta,'packages'))) {  
                 if(/^\w+response_\d+.*/) {  
                     my (undef, $partId, $responseId) = split(/_/,$_);  
                     if($beenHere{'p:'.$partId} ==  0) {  
                         $beenHere{'p:'.$partId}++;  
                         if(!defined($cache->{$currentSequence.':'.  
                                             $currentResourceID.':parts'})) {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':parts'}=$partId;  
                         } else {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':parts'}.=':'.$partId;  
                         }  
                     }  
                     if($beenHere{'r:'.$partId.':'.$responseId} == 0) {  
                         $beenHere{'r:'.$partId.':'.$responseId}++;  
                         if(!defined($cache->{$currentSequence.':'.  
                                              $currentResourceID.':'.$partId.  
                                              ':responseIDs'})) {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':'.$partId.':responseIDs'}=$responseId;  
                         } else {  
                             $cache->{$currentSequence.':'.$currentResourceID.  
                                      ':'.$partId.':responseIDs'}.=':'.  
                                                                   $responseId;  
                         }  
                     }  
                     if(/^optionresponse/ &&   
                        $beenHere{'o:'.$partId.':'.$currentResourceID} == 0) {  
                         $beenHere{'o:'.$partId.$currentResourceID}++;  
                         if(defined($cache->{'OptionResponses'})) {  
                             $cache->{'OptionResponses'}.= ':::'.  
                                 $currentSequence.':'.$currentResourceID.':'.  
                                 $partId.':'.$responseId;  
                         } else {  
                             $cache->{'OptionResponses'}= $currentSequence.':'.  
                                 $currentResourceID.':'.  
                                 $partId.':'.$responseId;  
                         }  
                     }  
                 }  
             }  
         }  
   
  # if resource == finish resource, then it is the end of a sequence/page  Get the MySQL id of a symb.
  if($currentResourceID eq $lastResourceID) {  
     # pop off last resource of sequence  
     $currentResourceID=pop(@currentResource);  
     $lastResourceID=pop(@finishResource);  
   
     if(defined($cache->{$currentSequence.':problems'})) {  
  # Capture sequence information here  
  $cache->{$currentSequence.':title'}=  
     $hash{'title_'.$currentResourceID};  
                 $cache->{$currentSequence.':source'}=  
                     $hash{'src_'.$currentResourceID};  
   
                 my $totalProblems=0;  
                 foreach my $currentProblem (split(/\:/,  
                                                $cache->{$currentSequence.  
                                                ':problems'})) {  
                     foreach (split(/\:/,$cache->{$currentSequence.':'.  
                                                    $currentProblem.  
                                                    ':parts'})) {  
                         $totalProblems++;  
                     }  
                 }  
  my @titleLength=split(//,$cache->{$currentSequence.  
                                                     ':title'});  
                 # $extra is 3 for problems correct and 3 for space  
                 # between problems correct and problem output  
                 my $extra = 6;  
  if(($totalProblems + $extra) > (scalar @titleLength)) {  
     $cache->{$currentSequence.':columnWidth'}=  
                         $totalProblems + $extra;  
  } else {  
     $cache->{$currentSequence.':columnWidth'}=  
                         (scalar @titleLength);  
  }  
     } else {  
                 # Remove sequence from list, if it contains no problems to  
                 # display.  
                 $cache->{'orderedSequences'}=~s/$currentSequence//;  
                 $cache->{'orderedSequences'}=~s/::/:/g;  
                 $cache->{'orderedSequences'}=~s/^:|:$//g;  
             }  
   
     $currentSequence=pop(@sequences);  Input: $symb
     if($currentSequence eq $topLevelSequenceNumber) {  
  last;  
     }  
         }  
   
  # MOVE!!!  Output: undef on error, integer $symb_id on success.
  # move to next resource  
  unless(defined($hash{'to_'.$currentResourceID})) {  
     # big problem, need to handle.  Next is probably wrong  
             my $errorMessage = 'Big problem in ';  
             $errorMessage .= 'loncoursedata::ProcessTopLevelMap.';  
             $errorMessage .= '  bighash to_$currentResourceID not defined!';  
             &Apache::lonnet::logthis($errorMessage);  
     last;  
  }  
  my @nextResources=();  
  foreach (split(/\,/,$hash{'to_'.$currentResourceID})) {  
             if(!defined($sequenceRecord{$currentSequence.':'.  
                                         $hash{'goesto_'.$_}})) {  
                 push(@nextResources, $hash{'goesto_'.$_});  
             }  
  }  
  push(@currentResource, @nextResources);  
  # Set the next resource to be processed  
  $currentResourceID=pop(@currentResource);  
     }  
   
     unless (untie(%hash)) {  =item &get_symb()
         &Apache::lonnet::logthis("<font color=blue>WARNING: ".  
                                  "Could not untie coursemap $fn (browse)".  Get the symb associated with a MySQL symb_id.
                                  ".</font>");   
   Input: $symb_id
   
   Output: undef on error, $symb on success.
   
   =cut
   
   ################################################
   ################################################
   
   my $have_read_symb_table = 0;
   my %ids_by_symb;
   my %symbs_by_id;
   
   sub get_symb_id {
       my ($symb) = @_;
       if (! $have_read_symb_table) {
           my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
               $ids_by_symb{$_->[1]}=$_->[0];
           }
           $have_read_symb_table = 1;
       }
       if (! exists($ids_by_symb{$symb})) {
           &Apache::lonmysql::store_row($symb_table,[undef,$symb]);
           undef(%ids_by_symb);
           my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
               $ids_by_symb{$_->[1]}=$_->[0];
           }
     }      }
       return $ids_by_symb{$symb} if(exists( $ids_by_symb{$symb}));
       return undef; # error
   }
   
     return 'OK';  sub get_symb {
       my ($symb_id) = @_;
       if (! exists($symbs_by_id{$symb_id})  || 
           ! defined($symbs_by_id{$symb_id}) ||
           $symbs_by_id{$symb_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($symb_table);
           foreach (@Result) {
               $symbs_by_id{$_->[0]}=$_->[1];
           }
       }
       return $symbs_by_id{$symb_id} if(exists( $symbs_by_id{$symb_id}));
       return undef; # error
 }  }
   
   ################################################
   ################################################
   
 =pod  =pod
   
 =item &ProcessClasslist()  =item &get_student_id()
   
 Taking the class list dumped from &DownloadClasslist(), all the   Get the MySQL id of a student.
 students and their non-class information is processed using the   
 &ProcessStudentInformation() function.  A date stamp is also recorded for  
 when the data was processed.  
   
 Takes data downloaded for a student and breaks it up into managable pieces and   Input: $sname, $dom
 stored in cache data.  The username, domain, class related date, PID,   
 full name, and section are all processed here.  
   
   Output: undef on error, integer $student_id on success.
   
 =over 4  =item &get_student()
   
 Input: $cache, $classlist, $courseID, $ChartDB, $c  Get student username:domain associated with the MySQL student_id.
   
 $cache: A hash pointer to store the data  Input: $student_id
   
 $classlist:  The hash of data collected about a student from   Output: undef on error, string $student (username:domain) on success.
 &DownloadClasslist().  The hash contains a list of students, a pointer   
 to a hash of student information for each student, and each student's section   
 number.  
   
 $courseID:  The course ID  =cut
   
 $ChartDB:  The name of the cache database file.  ################################################
   ################################################
   
 $c:  The connection class used to determine if an abort has been sent to the   my $have_read_student_table = 0;
 browser  my %ids_by_student;
   my %students_by_id;
   
   sub get_student_id {
       my ($sname,$sdom) = @_;
       my $student = $sname.':'.$sdom;
       if (! $have_read_student_table) {
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $ids_by_student{$_->[1]}=$_->[0];
           }
           $have_read_student_table = 1;
       }
       if (! exists($ids_by_student{$student})) {
           &populate_student_table();
           undef(%ids_by_student);
           undef(%students_by_id);
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $ids_by_student{$_->[1]}=$_->[0];
           }
       }
       return $ids_by_student{$student} if(exists( $ids_by_student{$student}));
       return undef; # error
   }
   
 Output: @names  sub get_student {
       my ($student_id) = @_;
       if (! exists($students_by_id{$student_id})  || 
           ! defined($students_by_id{$student_id}) ||
           $students_by_id{$student_id} eq '') {
           my @Result = &Apache::lonmysql::get_rows($student_table);
           foreach (@Result) {
               $students_by_id{$_->[0]}=$_->[1];
           }
       }
       return $students_by_id{$student_id} if(exists($students_by_id{$student_id}));
       return undef; # error
   }
   
 @names:  An array of students whose information has been processed, and are to   sub populate_student_table {
 be considered in an arbitrary order.      my ($courseid) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       &init_dbs($courseid,0);
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'INSERT IGNORE INTO '.$student_table.
           "(student,section,status) VALUES ";
       my $cdom = $env{'course.'.$courseid.'.domain'};
       my $cnum = $env{'course.'.$courseid.'.num'};
       my $classlist = &get_classlist($cdom,$cnum);
       my $student_count=0;
       while (my ($student,$data) = each %$classlist) {
           my ($section,$status) = ($data->[&CL_SECTION()],
                                    $data->[&CL_STATUS()]);
           if ($section eq '' || $section =~ /^\s*$/) {
               $section = 'none';
           }
           $request .= "('".$student."','".$section."','".$status."'),";
           $student_count++;
       }
       return if ($student_count == 0);
       chop($request);
       $dbh->do($request);
       if ($dbh->err()) {
           &Apache::lonnet::logthis("error ".$dbh->errstr().
                                    " occured executing \n".
                                    $request);
       }
       return;
   }
   
 =back  ################################################
   ################################################
   
   =pod
   
   =item &clear_internal_caches()
   
   Causes the internal caches used in get_student_id, get_student,
   get_symb_id, get_symb, get_part_id, and get_part to be undef'd.
   
   Needs to be called before the first operation with the MySQL database
   for a given Apache request.
   
 =cut  =cut
   
 sub ProcessClasslist {  ################################################
     my ($cache,$classlist,$courseID,$c)=@_;  ################################################
     my @names=();  sub clear_internal_caches {
       $have_read_part_table = 0;
     $cache->{'ClasslistTimeStamp'}=$classlist->{'lastDownloadTime'};      undef(%ids_by_part);
     if($classlist->{'UpToDate'} eq 'true') {      undef(%parts_by_id);
         return split(/:::/,$cache->{'NamesOfStudents'});;      $have_read_symb_table = 0;
     }      undef(%ids_by_symb);
       undef(%symbs_by_id);
       $have_read_student_table = 0;
       undef(%ids_by_student);
       undef(%students_by_id);
   }
   
   ################################################
   ################################################
   
   =pod
   
     foreach my $name (keys(%$classlist)) {  =item &update_full_student_data($sname,$sdom,$courseid)
         if($name =~ /\:section/ || $name =~ /\:studentInformation/ ||  
            $name eq '' || $name eq 'UpToDate' || $name eq 'lastDownloadTime') {  Does a lonnet::dump on a student to populate the courses tables.
   
   Input: $sname, $sdom, $courseid
   
   Output: $returnstatus
   
   $returnstatus is a string describing any errors that occured.  'okay' is the
   default.
   
   This subroutine loads a students data using lonnet::dump and inserts
   it into the MySQL database.  The inserts are done on three tables, 
   $fulldump_response_table, $fulldump_part_table, and $fulldump_timestamp_table.
   The INSERT calls are made directly by this subroutine, not through lonmysql 
   because we do a 'bulk'insert which takes advantage of MySQLs non-SQL 
   compliant INSERT command to insert multiple rows at a time.  
   If anything has gone wrong during this process, $returnstatus is updated with 
   a description of the error.
   
   Once the "fulldump" tables are updated, the tables used for chart and
   spreadsheet (which hold only the current state of the student on their
   homework, not historical data) are updated.  If all updates have occured 
   successfully, $student_table is updated to reflect the time of the update.
   
   Notice we do not insert the data and immediately query it.  This means it
   is possible for there to be data returned this first time that is not 
   available the second time.  CYA.
   
   =cut
   
   ################################################
   ################################################
   sub update_full_student_data {
       my ($sname,$sdom,$courseid) = @_;
       #
       # Set up database names
       &setup_table_names($courseid);
       #
       my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Download students data
       my $time_of_retrieval = time;
       my @tmp = &Apache::lonnet::dumpstore($courseid,$sdom,$sname);
       if (@tmp && $tmp[0] =~ /^error/) {
           $returnstatus = 'error retrieving full student data';
           return $returnstatus;
       } elsif (! @tmp) {
           $returnstatus = 'okay: no student data';
           return $returnstatus;
       }
       my %studentdata = @tmp;
       #
       # Get database handle and clean out the tables 
       my $dbh = &Apache::lonmysql::get_dbh();
       $dbh->do('DELETE FROM '.$fulldump_response_table.' WHERE student_id='.
                $student_id);
       $dbh->do('DELETE FROM '.$fulldump_part_table.' WHERE student_id='.
                $student_id);
       $dbh->do('DELETE FROM '.$fulldump_timestamp_table.' WHERE student_id='.
                $student_id);
       #
       # Parse and store the data into a form we can handle
       my $partdata;
       my $respdata;
       while (my ($key,$value) = each(%studentdata)) {
           next if ($key =~ /^(\d+):(resource$|subnum$|keys:)/);
           my ($transaction,$symb,$parameter) = split(':',$key);
           my $symb_id = &get_symb_id($symb);
           if ($parameter eq 'timestamp') {
               # We can deal with 'timestamp' right away
               my @timestamp_storage = ($symb_id,$student_id,
                                        $transaction,$value);
               my $store_command = 'INSERT IGNORE INTO '.$fulldump_timestamp_table.
                   " VALUES ('".join("','",@timestamp_storage)."');";
               $dbh->do($store_command);
               if ($dbh->err()) {
                   &Apache::lonnet::logthis('unable to execute '.$store_command);
                   &Apache::lonnet::logthis($dbh->errstr());
               }
             next;              next;
         }          } elsif ($parameter eq 'version') {
         if($c->aborted()) {              next;
             return ();          } elsif ($parameter =~ /^resource\.(.*)\.(tries|
         }                                                    award|
         push(@names,$name);                                                    awarded|
         my $studentInformation = $classlist->{$name.':studentInformation'},                                                    previous|
         my $sectionData = $classlist->{$name.':sections'},                                                    solved|
         my $date = $classlist->{$name},                                                    awarddetail|
         my ($studentName,$studentDomain) = split(/\:/,$name);                                                    submission|
                                                     submissiongrading|
         $cache->{$name.':username'}=$studentName;                                                    molecule)\s*$/x){
         $cache->{$name.':domain'}=$studentDomain;              # we do not have enough information to store an 
         # Initialize timestamp for student              # entire row, so we save it up until later.
         if(!defined($cache->{$name.':lastDownloadTime'})) {              my ($part_and_resp_id,$field) = ($1,$2);
             $cache->{$name.':lastDownloadTime'}='Not downloaded';              my ($part,$part_id,$resp,$resp_id);
             $cache->{$name.':updateTime'}=' Not updated';              if ($part_and_resp_id =~ /\./) {
         }                  ($part,$resp) = split(/\./,$part_and_resp_id);
                   $part_id = &get_part_id($part);
         my ($checkForError)=keys(%$studentInformation);                  $resp_id = &get_part_id($resp);
         if($checkForError =~ /^(con_lost|error|no_such_host)/i) {              } else {
             $cache->{$name.':error'}=                  $part_id = &get_part_id($part_and_resp_id);
                 'Could not download student environment data.';              }
             $cache->{$name.':fullname'}='';              # Deal with part specific data
             $cache->{$name.':id'}='';              if ($field =~ /^(tries|award|awarded|previous)$/) {
         } else {                  $partdata->{$symb_id}->{$part_id}->{$transaction}->{$field}=$value;
             $cache->{$name.':fullname'}=&ProcessFullName(              }
                                           $studentInformation->{'lastname'},              # deal with response specific data
                                           $studentInformation->{'generation'},              if (defined($resp_id) &&
                                           $studentInformation->{'firstname'},                  $field =~ /^(awarddetail|
                                           $studentInformation->{'middlename'});                               submission|
             $cache->{$name.':id'}=$studentInformation->{'id'};                               submissiongrading|
         }                               molecule)$/x) {
                   if ($field eq 'submission') {
         my ($end, $start)=split(':',$date);                      # We have to be careful with user supplied input.
         $courseID=~s/\_/\//g;                      # most of the time we are okay because it is escaped.
         $courseID=~s/^(\w)/\/$1/;                      # However, there is one wrinkle: submissions which end in
                       # and odd number of '\' cause insert errors to occur.  
         my $sec='';                      # Best trap this somehow...
         foreach my $key (keys (%$sectionData)) {                      $value = $dbh->quote($value);
             my $value = $sectionData->{$key};  
             if ($key=~/^$courseID(?:\/)*(\w+)*\_st$/) {  
                 my $tempsection=$1;  
                 if($key eq $courseID.'_st') {  
                     $tempsection='';  
                 }                  }
                 my ($dummy,$roleend,$rolestart)=split(/\_/,$value);                  if ($field eq 'submissiongrading' || 
                 if($roleend eq $end && $rolestart eq $start) {                      $field eq 'molecule') {
                     $sec = $tempsection;                      $respdata->{$symb_id}->{$part_id}->{$resp_id}->{$transaction}->{'response_specific'}=$field;
                     last;                      $respdata->{$symb_id}->{$part_id}->{$resp_id}->{$transaction}->{'response_specific_value'}=$value;
                   } else {
                       $respdata->{$symb_id}->{$part_id}->{$resp_id}->{$transaction}->{$field}=$value;
                 }                  }
             }              }
         }          }
       }
         my $status='Expired';      ##
         if(((!$end) || time < $end) && ((!$start) || (time > $start))) {      ## Store the part data
             $status='Active';      my $store_command = 'INSERT IGNORE INTO '.$fulldump_part_table.
           ' VALUES '."\n";
       my $store_rows = 0;
       while (my ($symb_id,$hash1) = each (%$partdata)) {
           while (my ($part_id,$hash2) = each (%$hash1)) {
               while (my ($transaction,$data) = each (%$hash2)) {
                   $store_command .= "('".join("','",$symb_id,$part_id,
                                               $student_id,
                                               $transaction,
                                               $data->{'tries'},
                                               $data->{'award'},
                                               $data->{'awarded'},
                                               $data->{'previous'})."'),";
                   $store_rows++;
               }
         }          }
         $cache->{$name.':Status'}=$status;      }
         $cache->{$name.':section'}=$sec;      if ($store_rows) {
           chop($store_command);
         if($sec eq '' || !defined($sec) || $sec eq ' ') {          $dbh->do($store_command);
             $sec = 'none';          if ($dbh->err) {
               $returnstatus = 'error storing part data';
               &Apache::lonnet::logthis('insert error '.$dbh->errstr());
               &Apache::lonnet::logthis("While attempting\n".$store_command);
           }
       }
       ##
       ## Store the response data
       $store_command = 'INSERT IGNORE INTO '.$fulldump_response_table.
           ' VALUES '."\n";
       $store_rows = 0;
       while (my ($symb_id,$hash1) = each (%$respdata)) {
           while (my ($part_id,$hash2) = each (%$hash1)) {
               while (my ($resp_id,$hash3) = each (%$hash2)) {
                   while (my ($transaction,$data) = each (%$hash3)) {
                       my $submission = $data->{'submission'};
                       # We have to be careful with user supplied input.
                       # most of the time we are okay because it is escaped.
                       # However, there is one wrinkle: submissions which end in
                       # and odd number of '\' cause insert errors to occur.  
                       # Best trap this somehow...
                       $submission = $dbh->quote($submission);
                       $store_command .= "('".
                           join("','",$symb_id,$part_id,
                                $resp_id,$student_id,
                                $transaction,
                                $data->{'awarddetail'},
                                $data->{'response_specific'},
                                $data->{'response_specific_value'},
                                $data->{'response_specific_2'},
                                $data->{'response_specific_value_2'}).
                                "',".$submission."),";
                       $store_rows++;
                   }
               }
         }          }
         if(defined($cache->{'sectionList'})) {      }
             if($cache->{'sectionList'} !~ /(^$sec:|^$sec$|:$sec$|:$sec:)/) {      if ($store_rows) {
                 $cache->{'sectionList'} .= ':'.$sec;          chop($store_command);
           $dbh->do($store_command);
           if ($dbh->err) {
               $returnstatus = 'error storing response data';
               &Apache::lonnet::logthis('insert error '.$dbh->errstr());
               &Apache::lonnet::logthis("While attempting\n".$store_command);
           }
       }
       ##
       ## Update the students "current" data in the performance 
       ## and parameters tables.
       my ($status,undef) = &store_student_data
           ($sname,$sdom,$courseid,
            &Apache::lonnet::convert_dump_to_currentdump(\%studentdata));
       if ($returnstatus eq 'okay' && $status ne 'okay') {
           $returnstatus = 'error storing current data:'.$status;
       } elsif ($status ne 'okay') {
           $returnstatus .= ' error storing current data:'.$status;
       }        
       ##
       ## Update the students time......
       if ($returnstatus eq 'okay') {
           &store_updatetime($student_id,$time_of_retrieval,$time_of_retrieval);
           if ($dbh->err) {
               if ($returnstatus eq 'okay') {
                   $returnstatus = 'error updating student time';
               } else {
                   $returnstatus = 'error updating student time';
             }              }
         } else {  
             $cache->{'sectionList'} = $sec;  
         }          }
     }      }
       return $returnstatus;
     $cache->{'ClasslistTimestamp'}=time;  
     $cache->{'NamesOfStudents'}=join(':::',@names);  
   
     return @names;  
 }  }
   
   ################################################
   ################################################
   
 =pod  =pod
   
 =item &ProcessStudentData()  =item &update_student_data()
   
 Takes the course data downloaded for a student in   Input: $sname, $sdom, $courseid
 &DownloadCourseInformation() and breaks it up into key value pairs  
 to be stored in the cached data.  The keys are comprised of the   
 $username:$domain:$keyFromCourseDatabase.  The student username:domain is  
 stored away signifying that the student's information has been downloaded and   
 can be reused from cached data.  
   
 =over 4  Output: $returnstatus, \%student_data
   
 Input: $cache, $courseData, $name  $returnstatus is a string describing any errors that occured.  'okay' is the
   default.
   \%student_data is the data returned by a call to lonnet::currentdump.
   
   This subroutine loads a students data using lonnet::currentdump and inserts
   it into the MySQL database.  The inserts are done on two tables, 
   $performance_table and $parameters_table.  $parameters_table holds the data 
   that is not included in $performance_table.  See the description of 
   $performance_table elsewhere in this file.  The INSERT calls are made
   directly by this subroutine, not through lonmysql because we do a 'bulk'
   insert which takes advantage of MySQLs non-SQL compliant INSERT command to 
   insert multiple rows at a time.  If anything has gone wrong during this
   process, $returnstatus is updated with a description of the error and
   \%student_data is returned.  
   
   Notice we do not insert the data and immediately query it.  This means it
   is possible for there to be data returned this first time that is not 
   available the second time.  CYA.
   
 $cache: A hash pointer to store data  =cut
   
 $courseData:  A hash pointer that points to the course data downloaded for a   ################################################
 student.  ################################################
   sub update_student_data {
       my ($sname,$sdom,$courseid) = @_;
       #
       # Set up database names
       &setup_table_names($courseid);
       #
       my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Download students data
       my $time_of_retrieval = time;
       my @tmp = &Apache::lonnet::currentdump($courseid,$sdom,$sname);
       if ((scalar(@tmp) > 0) && ($tmp[0] =~ /^error:/)) {
           &Apache::lonnet::logthis('error getting data for '.
                                    $sname.':'.$sdom.' in course '.$courseid.
                                    ':'.$tmp[0]);
           $returnstatus = 'error getting data';
           return ($returnstatus,undef);
       }
       if (scalar(@tmp) < 1) {
           return ('no data',undef);
       }
       my %student_data = @tmp;
       my @Results = &store_student_data($sname,$sdom,$courseid,\%student_data);
       #
       # Set the students update time
       if ($Results[0] eq 'okay') {
           &store_updatetime($student_id,$time_of_retrieval);
       }
       #
       return @Results;
   }
   
 $name:  username:domain  sub store_updatetime {
       my ($student_id,$updatetime,$fullupdatetime)=@_;
       my $values = '';
       if (defined($updatetime)) {
           $values = 'updatetime='.$updatetime.' ';
       }
       if (defined($fullupdatetime)) {
           if ($values ne '') {
               $values .= ',';
           }
           $values .= 'fullupdatetime='.$fullupdatetime.' ';
       }
       return if ($values eq '');
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'UPDATE '.$student_table.' SET '.$values.
           ' WHERE student_id='.$student_id.' LIMIT 1';
       $dbh->do($request);
   }
   
 Output: None  sub store_student_data {
       my ($sname,$sdom,$courseid,$student_data) = @_;
       #
       my $student_id = &get_student_id($sname,$sdom);
       my $student = $sname.':'.$sdom;
       #
       my $returnstatus = 'okay';
       #
       # Remove all of the students data from the table
       my $dbh = &Apache::lonmysql::get_dbh();
       $dbh->do('DELETE FROM '.$performance_table.' WHERE student_id='.
                $student_id);
       $dbh->do('DELETE FROM '.$parameters_table.' WHERE student_id='.
                $student_id);
       #
       # Store away the data
       #
       my $starttime = Time::HiRes::time;
       my $elapsed = 0;
       my $rows_stored;
       my $store_parameters_command  = 'INSERT IGNORE INTO '.$parameters_table.
           ' VALUES '."\n";
       my $num_parameters = 0;
       my $store_performance_command = 'INSERT IGNORE INTO '.$performance_table.
           ' VALUES '."\n";
       return ('error',undef) if (! defined($dbh));
       while (my ($current_symb,$param_hash) = each(%{$student_data})) {
           #
           # make sure the symb is set up properly
           my $symb_id = &get_symb_id($current_symb);
           #
           # Parameters
           while (my ($parameter,$value) = each(%$param_hash)) {
               if ($parameter !~ /(timestamp|resource\.(.*)\.(solved|tries|awarded|award|awarddetail|previous))/) {
                   my $sql_parameter = "('".join("','",
                                                 $symb_id,$student_id,
                                                 $parameter)."',".
                                                     $dbh->quote($value)."),\n";
                   $num_parameters ++;
                   if ($sql_parameter !~ /''/) {
                       $store_parameters_command .= $sql_parameter;
                       #$rows_stored++;
                   }
               }
           }
           # Performance
           my %stored;
           while (my ($parameter,$value) = each(%$param_hash)) {
               next if ($parameter !~ /^resource\.(.*)\.(solved|awarded)$/);
               my $part  = $1;
       my $which = $2;
       next if ($part =~ /\./);
               next if (exists($stored{$part}));
               $stored{$part}++;
               #
               my $part_id = &get_part_id($part);
               next if (!defined($part_id));
       
               my ($solved,$awarded);
       if ($which eq 'solved') {
    $solved  = $value;
    $awarded = $param_hash->{'resource.'.$part.'.awarded'};
       } else {
    $solved  = $param_hash->{'resource.'.$part.'.solved'};
    $awarded = $value;
       }
               my $award   = $param_hash->{'resource.'.$part.'.award'};
               my $awarddetail = $param_hash->{'resource.'.$part.'.awarddetail'};
               my $timestamp = $param_hash->{'timestamp'};
               #
               $solved      = '' if (! defined($solved));
               $tries       = '' if (! defined($tries));
               $awarded     = '' if (! defined($awarded));
               $award       = '' if (! defined($award));
               $awarddetail = '' if (! defined($awarddetail));
               my $sql_performance = 
                   "('".join("','",$symb_id,$student_id,$part_id,$part,
                                   $solved,$tries,$awarded,$award,
                                   $awarddetail,$timestamp)."'),\n";
               $store_performance_command .= $sql_performance;
               $rows_stored++;
           }
       }
       if (! $rows_stored) { return ($returnstatus, undef); }
       $store_parameters_command =~ s|,\n$||;
       $store_performance_command =~ s|,\n$||;
       my $start = Time::HiRes::time;
       $dbh->do($store_performance_command);
       if ($dbh->err()) {
           &Apache::lonnet::logthis('performance bigass insert error:'.
                                    $dbh->errstr());
           &Apache::lonnet::logthis('command = '.$/.$store_performance_command);
           $returnstatus = 'error: unable to insert performance into database';
           return ($returnstatus,$student_data);
       }
       $dbh->do($store_parameters_command) if ($num_parameters>0);
       if ($dbh->err()) {
           &Apache::lonnet::logthis('parameters bigass insert error:'.
                                    $dbh->errstr());
           &Apache::lonnet::logthis('command = '.$/.$store_parameters_command);
           &Apache::lonnet::logthis('rows_stored = '.$rows_stored);
           &Apache::lonnet::logthis('student_id = '.$student_id);
           $returnstatus = 'error: unable to insert parameters into database';
           return ($returnstatus,$student_data);
       }
       $elapsed += Time::HiRes::time - $start;
       return ($returnstatus,$student_data);
   }
   
 *NOTE:  There is no output, but an error message is stored away in the cache   ######################################
 data.  This is checked in &FormatStudentData().  The key username:domain:error   ######################################
 will only exist if an error occured.  The error is an error from   
 &DownloadCourseInformation().  
   
 =back  =pod
   
 =cut  =item &ensure_tables_are_set_up($courseid)
   
 sub ProcessStudentData {  Checks to be sure the MySQL tables for the given class are set up.
     my ($cache,$courseData,$name)=@_;  If $courseid is omitted it will be obtained from the environment.
   
     if(!&CheckDateStampError($courseData, $cache, $name)) {  Returns nothing on success and 'error' on failure
         return;  
     }  
   
     foreach (keys %$courseData) {  =cut
         $cache->{$_}=$courseData->{$_};  
     }  
   
     return;  ######################################
   ######################################
   sub ensure_tables_are_set_up {
       my ($courseid) = @_;
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       # 
       # Clean out package variables
       &setup_table_names($courseid);
       #
       # if the tables do not exist, make them
       my @CurrentTable = &Apache::lonmysql::tables_in_db();
       my ($found_symb,$found_student,$found_part,
           $found_performance,$found_parameters,$found_fulldump_part,
           $found_fulldump_response,$found_fulldump_timestamp,
           $found_weight);
       foreach (@CurrentTable) {
           $found_symb        = 1 if ($_ eq $symb_table);
           $found_student     = 1 if ($_ eq $student_table);
           $found_part        = 1 if ($_ eq $part_table);
           $found_performance = 1 if ($_ eq $performance_table);
           $found_parameters  = 1 if ($_ eq $parameters_table);
           $found_fulldump_part      = 1 if ($_ eq $fulldump_part_table);
           $found_fulldump_response  = 1 if ($_ eq $fulldump_response_table);
           $found_fulldump_timestamp = 1 if ($_ eq $fulldump_timestamp_table);
           $found_weight      = 1 if ($_ eq $weight_table);
       }
       if (!$found_symb          || 
           !$found_student       || !$found_part              ||
           !$found_performance   || !$found_parameters        ||
           !$found_fulldump_part || !$found_fulldump_response ||
           !$found_fulldump_timestamp || !$found_weight ) {
           if (&init_dbs($courseid,1)) {
               return 'error';
           }
       }
 }  }
   
 sub ExtractStudentData {  ################################################
     my ($input, $output, $data, $name)=@_;  ################################################
   
     if(!&CheckDateStampError($input, $data, $name)) {  =pod
         return;  
     }  
   
     my ($username,$domain)=split(':',$name);  =item &ensure_current_data()
   
     my $Version;  Input: $sname, $sdom, $courseid
     my $problemsCorrect = 0;  
     my $totalProblems   = 0;  
     my $problemsSolved  = 0;  
     my $numberOfParts   = 0;  
     my $totalAwarded    = 0;  
     foreach my $sequence (split(':', $data->{'orderedSequences'})) {  
         foreach my $problemID (split(':', $data->{$sequence.':problems'})) {  
             my $problem = $data->{$problemID.':problem'};  
             my $LatestVersion = $input->{$name.':version:'.$problem};  
   
             # Output dashes for all the parts of this problem if there  
             # is no version information about the current problem.  
             if(!$LatestVersion) {  
                 foreach my $part (split(/\:/,$data->{$sequence.':'.  
                                                       $problemID.  
                                                       ':parts'})) {  
                     $output->{$name.':'.$problemID.':'.$part.':tries'} = 0;  
                     $output->{$name.':'.$problemID.':'.$part.':awarded'} = 0;  
                     $output->{$name.':'.$problemID.':'.$part.':code'} = ' ';  
                     $totalProblems++;  
                 }  
                 $output->{$name.':'.$problemID.':NoVersion'} = 'true';  
                 next;  
             }  
   
             my %partData=undef;  Output: $status, $data
             # Initialize part data, display skips correctly  
             # Skip refers to when a student made no submissions on that  
             # part/problem.  
             foreach my $part (split(/\:/,$data->{$sequence.':'.  
                                                  $problemID.  
                                                  ':parts'})) {  
                 $partData{$part.':tries'}=0;  
                 $partData{$part.':code'}=' ';  
                 $partData{$part.':awarded'}=0;  
                 $partData{$part.':timestamp'}=0;  
                 foreach my $response (split(':', $data->{$sequence.':'.  
                                                          $problemID.':'.  
                                                          $part.':responseIDs'})) {  
                     $partData{$part.':'.$response.':submission'}='';  
                 }  
             }  
   
             # Looping through all the versions of each part, starting with the  This routine ensures the data for a given student is up to date.
             # oldest version.  Basically, it gets the most recent   The $student_table is queried to determine the time of the last update.  
             # set of grade data for each part.  If the students data is out of date, &update_student_data() is called.  
             my @submissions = ();  The return values from the call to &update_student_data() are returned.
     for(my $Version=1; $Version<=$LatestVersion; $Version++) {  
                 foreach my $part (split(/\:/,$data->{$sequence.':'.  
                                                      $problemID.  
                                                      ':parts'})) {  
   
                     if(!defined($input->{"$name:$Version:$problem".  
                                          ":resource.$part.solved"})) {  
                         # No grade for this submission, so skip  
                         next;  
                     }  
   
                     my $tries=0;  
                     my $code=' ';  
                     my $awarded=0;  
   
                     $tries = $input->{$name.':'.$Version.':'.$problem.  
                                       ':resource.'.$part.'.tries'};  
                     $awarded = $input->{$name.':'.$Version.':'.$problem.  
                                         ':resource.'.$part.'.awarded'};  
   
                     $partData{$part.':awarded'}=($awarded) ? $awarded : 0;  
                     $partData{$part.':tries'}=($tries) ? $tries : 0;  
   
                     $partData{$part.':timestamp'}=$input->{$name.':'.$Version.':'.  
                                                            $problem.  
                                                            ':timestamp'};  
                     if(!$input->{$name.':'.$Version.':'.$problem.':resource.'.$part.  
                                  '.previous'}) {  
                         foreach my $response (split(':',  
                                                    $data->{$sequence.':'.  
                                                            $problemID.':'.  
                                                            $part.':responseIDs'})) {  
                             @submissions=($input->{$name.':'.$Version.':'.  
                                                    $problem.  
                                                    ':resource.'.$part.'.'.  
                                                    $response.'.submission'},  
                                           @submissions);  
                         }  
                     }  
   
                     my $val = $input->{$name.':'.$Version.':'.$problem.  
                                        ':resource.'.$part.'.solved'};  
                     if    ($val eq 'correct_by_student')   {$code = '*';}   
                     elsif ($val eq 'correct_by_override')  {$code = '+';}  
                     elsif ($val eq 'incorrect_attempted')  {$code = '.';}   
                     elsif ($val eq 'incorrect_by_override'){$code = '-';}  
                     elsif ($val eq 'excused')              {$code = 'x';}  
                     elsif ($val eq 'ungraded_attempted')   {$code = '#';}  
                     else                                   {$code = ' ';}  
                     $partData{$part.':code'}=$code;  
                 }  
             }  
   
             foreach my $part (split(/\:/,$data->{$sequence.':'.$problemID.  =cut
                                                  ':parts'})) {  
                 $output->{$name.':'.$problemID.':'.$part.':wrong'} =   
                     $partData{$part.':tries'};  
   
                 if($partData{$part.':code'} eq '*') {  
                     $output->{$name.':'.$problemID.':'.$part.':wrong'}--;  
                     $problemsCorrect++;  
                 } elsif($partData{$part.':code'} eq '+') {  
                     $output->{$name.':'.$problemID.':'.$part.':wrong'}--;  
                     $problemsCorrect++;  
                 }  
   
                 $output->{$name.':'.$problemID.':'.$part.':tries'} =   ################################################
                     $partData{$part.':tries'};  ################################################
                 $output->{$name.':'.$problemID.':'.$part.':code'} =  sub ensure_current_data {
                     $partData{$part.':code'};      my ($sname,$sdom,$courseid) = @_;
                 $output->{$name.':'.$problemID.':'.$part.':awarded'} =      my $status = 'okay';   # return value
                     $partData{$part.':awarded'};      #
                 $totalAwarded += $partData{$part.':awarded'};      $courseid = $env{'request.course.id'} if (! defined($courseid));
                 $output->{$name.':'.$problemID.':'.$part.':timestamp'} =      &ensure_tables_are_set_up($courseid);
                     $partData{$part.':timestamp'};      #
                 foreach my $response (split(':', $data->{$sequence.':'.      # Get the update time for the user
                                                          $problemID.':'.      my $updatetime = 0;
                                                          $part.':responseIDs'})) {      my $modifiedtime = &Apache::lonnet::GetFileTimestamp
                     $output->{$name.':'.$problemID.':'.$part.':'.$response.          ($sdom,$sname,$courseid.'.db',
                               ':submission'}=join(':::',@submissions);           $Apache::lonnet::perlvar{'lonUsersDir'});
                 }      #
       my $student_id = &get_student_id($sname,$sdom);
       my @Result = &Apache::lonmysql::get_rows($student_table,
                                                "student_id ='$student_id'");
       my $data = undef;
       if (@Result) {
           $updatetime = $Result[0]->[5];  # Ack!  This is dumb!
       }
       if ($modifiedtime > $updatetime) {
           ($status,$data) = &update_student_data($sname,$sdom,$courseid);
       }
       return ($status,$data);
   }
   
                 if($partData{$part.':code'} ne 'x') {  ################################################
                     $totalProblems++;  ################################################
                 }  
             }  
         }  
   
         $output->{$name.':'.$sequence.':problemsCorrect'} = $problemsCorrect;  =pod
         $problemsSolved += $problemsCorrect;  
  $problemsCorrect=0;  
     }  
   
     $output->{$name.':problemsSolved'} = $problemsSolved;  =item &ensure_current_full_data($sname,$sdom,$courseid)
     $output->{$name.':totalProblems'} = $totalProblems;  
     $output->{$name.':totalAwarded'} = $totalAwarded;  
   
     return;  Input: $sname, $sdom, $courseid
 }  
   
 sub LoadDiscussion {  Output: $status
     my ($courseID)=@_;  
     my %Discuss=();  This routine ensures the fulldata (the data from a lonnet::dump, not a
     my %contrib=&Apache::lonnet::dump(  lonnet::currentdump) for a given student is up to date.
                 $courseID,  The $student_table is queried to determine the time of the last update.  
                 $ENV{'course.'.$courseID.'.domain'},  If the students fulldata is out of date, &update_full_student_data() is
                 $ENV{'course.'.$courseID.'.num'});  called.  
     
     #my %contrib=&DownloadCourseInformation($name, $courseID, 0);  The return value from the call to &update_full_student_data() is returned.
   
     foreach my $temp(keys %contrib) {  
  if ($temp=~/^version/) {  
     my $ver=$contrib{$temp};  
     my ($dummy,$prb)=split(':',$temp);  
     for (my $idx=1; $idx<=$ver; $idx++ ) {  
  my $name=$contrib{"$idx:$prb:sendername"};  
  $Discuss{"$name:$prb"}=$idx;  
     }  
  }  
     }         
   
     return \%Discuss;  =cut
   
   ################################################
   ################################################
   sub ensure_current_full_data {
       my ($sname,$sdom,$courseid) = @_;
       my $status = 'okay';   # return value
       #
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       &ensure_tables_are_set_up($courseid);
       #
       # Get the update time for the user
       my $modifiedtime = &Apache::lonnet::GetFileTimestamp
           ($sdom,$sname,$courseid.'.db',
            $Apache::lonnet::perlvar{'lonUsersDir'});
       #
       my $student_id = &get_student_id($sname,$sdom);
       my @Result = &Apache::lonmysql::get_rows($student_table,
                                                "student_id ='$student_id'");
       my $updatetime;
       if (@Result && ref($Result[0]) eq 'ARRAY') {
           $updatetime = $Result[0]->[6];
       }
       if (! defined($updatetime) || $modifiedtime > $updatetime) {
           $status = &update_full_student_data($sname,$sdom,$courseid);
       }
       return $status;
 }  }
   
 # ----- END PROCESSING FUNCTIONS ---------------------------------------  ################################################
   ################################################
   
 =pod  =pod
   
 =head1 HELPER FUNCTIONS  =item &get_student_data_from_performance_cache()
   
 These are just a couple of functions do various odd and end   Input: $sname, $sdom, $symb, $courseid
 jobs.  
   
 =cut  Output: hash reference containing the data for the given student.
   If $symb is undef, all the students data is returned.
   
 # ----- HELPER FUNCTIONS -----------------------------------------------  This routine is the heart of the local caching system.  See the description
   of $performance_table, $symb_table, $student_table, and $part_table.  The
   main task is building the MySQL request.  The tables appear in the request
   in the order in which they should be parsed by MySQL.  When searching
   on a student the $student_table is used to locate the 'student_id'.  All
   rows in $performance_table which have a matching 'student_id' are returned,
   with data from $part_table and $symb_table which match the entries in
   $performance_table, 'part_id' and 'symb_id'.  When searching on a symb,
   the $symb_table is processed first, with matching rows grabbed from 
   $performance_table and filled in from $part_table and $student_table in
   that order.  
   
 sub CheckDateStampError {  Running 'EXPLAIN ' on the 'SELECT' statements generated can be quite 
     my ($courseData, $cache, $name)=@_;  interesting, especially if you play with the order the tables are listed.  
     if($courseData->{$name.':UpToDate'} eq 'true') {  
         $cache->{$name.':lastDownloadTime'} =   
             $courseData->{$name.':lastDownloadTime'};  
         if($courseData->{$name.':lastDownloadTime'} eq 'Not downloaded') {  
             $cache->{$name.':updateTime'} = ' Not updated';  
         } else {  
             $cache->{$name.':updateTime'}=  
                 localtime($courseData->{$name.':lastDownloadTime'});  
         }  
         return 0;  
     }  
   
     $cache->{$name.':lastDownloadTime'}=$courseData->{$name.':lastDownloadTime'};  =cut
     if($courseData->{$name.':lastDownloadTime'} eq 'Not downloaded') {  
         $cache->{$name.':updateTime'} = ' Not updated';  
     } else {  
         $cache->{$name.':updateTime'}=  
             localtime($courseData->{$name.':lastDownloadTime'});  
     }  
   
     if(defined($courseData->{$name.':error'})) {  ################################################
         $cache->{$name.':error'}=$courseData->{$name.':error'};  ################################################
         return 0;  sub get_student_data_from_performance_cache {
       my ($sname,$sdom,$symb,$courseid)=@_;
       my $student = $sname.':'.$sdom if (defined($sname) && defined($sdom));
       &setup_table_names($courseid);
       #
       # Return hash
       my $studentdata;
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = "SELECT ".
           "d.symb,a.part,a.solved,a.tries,a.awarded,a.award,a.awarddetail,".
               "a.timestamp ";
       if (defined($student)) {
           $request .= "FROM $student_table AS b ".
               "LEFT JOIN $performance_table AS a ON b.student_id=a.student_id ".
   #            "LEFT JOIN $part_table AS c ON c.part_id = a.part_id ".
               "LEFT JOIN $symb_table AS d ON d.symb_id = a.symb_id ".
                   "WHERE student='$student'";
           if (defined($symb) && $symb ne '') {
               $request .= " AND d.symb=".$dbh->quote($symb);
           }
       } elsif (defined($symb) && $symb ne '') {
           $request .= "FROM $symb_table as d ".
               "LEFT JOIN $performance_table AS a ON d.symb_id=a.symb_id ".
   #            "LEFT JOIN $part_table    AS c ON c.part_id = a.part_id ".
               "LEFT JOIN $student_table AS b ON b.student_id = a.student_id ".
                   "WHERE symb='".$dbh->quote($symb)."'";
       }
       my $starttime = Time::HiRes::time;
       my $rows_retrieved = 0;
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($sth->err()) {
           &Apache::lonnet::logthis("Unable to execute MySQL request:");
           &Apache::lonnet::logthis("\n".$request."\n");
           &Apache::lonnet::logthis("error is:".$sth->errstr());
           return undef;
       }
       foreach my $row (@{$sth->fetchall_arrayref}) {
           $rows_retrieved++;
           my ($symb,$part,$solved,$tries,$awarded,$award,$awarddetail,$time) = 
               (@$row);
           my $base = 'resource.'.$part;
           $studentdata->{$symb}->{$base.'.solved'}  = $solved;
           $studentdata->{$symb}->{$base.'.tries'}   = $tries;
           $studentdata->{$symb}->{$base.'.awarded'} = $awarded;
           $studentdata->{$symb}->{$base.'.award'}   = $award;
           $studentdata->{$symb}->{$base.'.awarddetail'} = $awarddetail;
           $studentdata->{$symb}->{'timestamp'} = $time if (defined($time) && $time ne '');
       }
       ## Get misc parameters
       $request = 'SELECT c.symb,a.parameter,a.value '.
           "FROM $student_table AS b ".
           "LEFT JOIN $parameters_table AS a ON b.student_id=a.student_id ".
           "LEFT JOIN $symb_table AS c ON c.symb_id = a.symb_id ".
           "WHERE student='$student'";
       if (defined($symb) && $symb ne '') {
           $request .= " AND c.symb=".$dbh->quote($symb);
       }
       $sth = $dbh->prepare($request);
       $sth->execute();
       if ($sth->err()) {
           &Apache::lonnet::logthis("Unable to execute MySQL request:");
           &Apache::lonnet::logthis("\n".$request."\n");
           &Apache::lonnet::logthis("error is:".$sth->errstr());
           if (defined($symb) && $symb ne '') {
               $studentdata = $studentdata->{$symb};
           }
           return $studentdata;
       }
       #
       foreach my $row (@{$sth->fetchall_arrayref}) {
           $rows_retrieved++;
           my ($symb,$parameter,$value) = (@$row);
           $studentdata->{$symb}->{$parameter}  = $value;
       }
       #
       if (defined($symb) && $symb ne '') {
           $studentdata = $studentdata->{$symb};
     }      }
       return $studentdata;
     return 1;  
 }  }
   
   ################################################
   ################################################
   
 =pod  =pod
   
 =item &ProcessFullName()  =item &get_current_state()
   
 Takes lastname, generation, firstname, and middlename (or some partial  Input: $sname,$sdom,$symb,$courseid
 set of this data) and returns the full name version as a string.  Format  
 is Lastname generation, firstname middlename or a subset of this.  
   
 =cut  Output: Described below
   
 sub ProcessFullName {  Retrieve the current status of a students performance.  $sname and
     my ($lastname, $generation, $firstname, $middlename)=@_;  $sdom are the only required parameters.  If $symb is undef the results
     my $Str = '';  of an &Apache::lonnet::currentdump() will be returned.  
   If $courseid is undef it will be retrieved from the environment.
   
   The return structure is based on &Apache::lonnet::currentdump.  If
   $symb is unspecified, all the students data is returned in a hash of
   the form:
   ( 
     symb1 => { param1 => value1, param2 => value2 ... },
     symb2 => { param1 => value1, param2 => value2 ... },
   )
   
   If $symb is specified, a hash of 
   (
     param1 => value1, 
     param2 => value2,
   )
   is returned.
   
     if($lastname ne '') {  If no data is found for $symb, or if the student has no performance data,
  $Str .= $lastname.' ';  an empty list is returned.
  if($generation ne '') {  
     $Str .= $generation;  =cut
  } else {  
     chop($Str);  ################################################
  }  ################################################
  $Str .= ', ';  sub get_current_state {
  if($firstname ne '') {      my ($sname,$sdom,$symb,$courseid,$forcedownload)=@_;
     $Str .= $firstname.' ';      #
  }      $courseid = $env{'request.course.id'} if (! defined($courseid));
  if($middlename ne '') {      #
     $Str .= $middlename;      return () if (! defined($sname) || ! defined($sdom));
  } else {      #
     chop($Str);      my ($status,$data) = &ensure_current_data($sname,$sdom,$courseid);
     if($firstname eq '') {  #    &Apache::lonnet::logthis
  chop($Str);  #        ('sname = '.$sname.
     }  #         ' domain = '.$sdom.
  }  #         ' status = '.$status.
   #         ' data is '.(defined($data)?'defined':'undefined'));
   #    while (my ($symb,$hash) = each(%$data)) {
   #        &Apache::lonnet::logthis($symb."\n----------------------------------");
   #        while (my ($key,$value) = each (%$hash)) {
   #            &Apache::lonnet::logthis("   ".$key." = ".$value);
   #        }
   #    }
       #
       if (defined($data) && defined($symb) && ref($data->{$symb})) {
           return %{$data->{$symb}};
       } elsif (defined($data) && ! defined($symb) && ref($data)) {
           return %$data;
       } 
       if ($status eq 'no data') {
           return ();
     } else {      } else {
  if($firstname ne '') {          if ($status ne 'okay' && $status ne '') {
     $Str .= $firstname.' ';              &Apache::lonnet::logthis('status = '.$status);
  }              return ();
  if($middlename ne '') {          }
     $Str .= $middlename.' ';          my $returnhash = &get_student_data_from_performance_cache($sname,$sdom,
  }                                                        $symb,$courseid);
  if($generation ne '') {          return %$returnhash if (defined($returnhash));
     $Str .= $generation;  
  } else {  
     chop($Str);  
  }  
     }      }
       return ();
     return $Str;  
 }  }
   
   ################################################
   ################################################
   
 =pod  =pod
   
 =item &TestCacheData()  =item &get_problem_statistics()
   
   Gather data on a given problem.  The database is assumed to be 
   populated and all local caching variables are assumed to be set
   properly.  This means you need to call &ensure_current_data for
   the students you are concerned with prior to calling this routine.
   
 Determine if the cache database can be accessed with a tie.  It waits up to  Inputs: $Sections, $status, $symb, $part, $courseid, $starttime, $endtime
 ten seconds before returning failure.  This function exists to help with  
 the problems with stopping the data download.  When an abort occurs and the  
 user quickly presses a form button and httpd child is created.  This  
 child needs to wait for the other to finish (hopefully within ten seconds).  
   
 =over 4  =over 4
   
 Input: $ChartDB  =item $Sections Array ref containing section names for students.  
   'all' is allowed to be the first (and only) item in the array.
   
   =item $status String describing the status of students
   
   =item $symb is the symb for the problem.
   
   =item $part is the part id you need statistics for
   
   =item $courseid is the course id, of course!
   
 $ChartDB: The name of the cache database to be opened  =item $starttime and $endtime are unix times which to use to limit
   the statistical data.
   
   =back
   
   Outputs: See the code for up to date information.  A hash reference is
   returned.  The hash has the following keys defined:
   
   =over 4
   
 Output: -1, 0, 1  =item num_students The number of students attempting the problem
         
   =item tries The total number of tries for the students
         
   =item max_tries The maximum number of tries taken
         
   =item mean_tries The average number of tries
         
   =item num_solved The number of students able to solve the problem
         
   =item num_override The number of students whose answer is 'correct_by_override'
         
   =item deg_of_diff The degree of difficulty of the problem
         
   =item std_tries The standard deviation of the number of tries
         
   =item skew_tries The skew of the number of tries
   
 -1: Couldn't tie database  =item per_wrong The number of students attempting the problem who were not
  0: Use cached data  able to answer it correctly.
  1: New cache database created, use that.  
   
 =back  =back
   
 =cut  =cut
   
 sub TestCacheData {  ################################################
     my ($ChartDB,$isRecalculate,$totalDelay)=@_;  ################################################
     my $isCached=-1;  sub get_problem_statistics {
     my %testData;      my ($Sections,$status,$symb,$part,$courseid,$starttime,$endtime) = @_;
     my $tieTries=0;      return if (! defined($symb) || ! defined($part));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       my $part_id = &get_part_id($part);
       my $stats_table = $courseid.'_problem_stats';
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       #
       # Clean out the table
       $dbh->do('DROP TABLE '.$stats_table);  # May return an error
       my $request = 
           'CREATE TEMPORARY TABLE '.$stats_table.' '.
           'SELECT a.student_id,a.solved,a.award,a.awarded,a.tries '.
           'FROM '.$performance_table.' AS a ';
       #
       # See if we need to include some requirements on the students
       if ((defined($Sections) && lc($Sections->[0]) ne 'all') || 
           (defined($status)   && lc($status)        ne 'any')) {
           $request .= 'NATURAL LEFT JOIN '.$student_table.' AS b ';
       }
       $request .= ' WHERE a.symb_id='.$symb_id.' AND a.part_id='.$part_id;
       #
       # Limit the students included to those specified
       if (defined($Sections) && lc($Sections->[0]) ne 'all') {
           $request .= ' AND ('.
               join(' OR ', map { "b.section='".$_."'" } @$Sections
                    ).')';
       }
       if (defined($status) && lc($status) ne 'any') {
           $request .= " AND b.status='".$status."'";
       }
       #
       # Limit by starttime and endtime
       my $time_requirements = undef;
       if (defined($starttime)) {
           $time_requirements .= 'a.timestamp>='.$starttime;
           if (defined($endtime)) {
               $time_requirements .= ' AND a.timestamp<='.$endtime;
           }
       } elsif (defined($endtime)) {
           $time_requirements .= 'a.timestamp<='.$endtime;
       }
       if (defined($time_requirements)) {
           $request .= ' AND '.$time_requirements;
       }
       #
       # Finally, execute the request to create the temporary table
       $dbh->do($request);
       #
       # Collect the first suite of statistics
       $request = 'SELECT COUNT(*),SUM(tries),'.
           'AVG(tries),STD(tries) '.
           'FROM '.$stats_table;
       my ($num,$tries,$mean,$STD) = &execute_SQL_request
           ($dbh,$request);
       #
       $request = 'SELECT MAX(tries),MIN(tries) FROM '.$stats_table.
           ' WHERE awarded>0';
       if (defined($time_requirements)) {
           $request .= ' AND '.$time_requirements;
       }
       my ($max,$min) = &execute_SQL_request($dbh,$request);
       #
       $request = 'SELECT SUM(awarded) FROM '.$stats_table;
       if (defined($time_requirements)) {
           $request .= ' AND '.$time_requirements;
       }
       my ($Solved) = &execute_SQL_request($dbh,$request);
       #
       $request = 'SELECT SUM(awarded) FROM '.$stats_table.
           " WHERE solved='correct_by_override'";
       if (defined($time_requirements)) {
           $request .= ' AND '.$time_requirements;
       }
       my ($solved) = &execute_SQL_request($dbh,$request);
       #
       $Solved -= $solved;
       #
       $num    = 0 if (! defined($num));
       $tries  = 0 if (! defined($tries));
       $max    = 0 if (! defined($max));
       $min    = 0 if (! defined($min));
       $STD    = 0 if (! defined($STD));
       $Solved = 0 if (! defined($Solved) || $Solved < 0);
       $solved = 0 if (! defined($solved));
       #
       # Compute the more complicated statistics
       my $DegOfDiff = 'nan';
       $DegOfDiff = 1-($Solved)/$tries if ($tries>0);
       #
       my $SKEW = 'nan';
       my $wrongpercent = 0;
       my $numwrong = 'nan';
       if ($num > 0) {
           ($SKEW) = &execute_SQL_request($dbh,'SELECT SQRT(SUM('.
                                        'POWER(tries - '.$STD.',3)'.
                                        '))/'.$num.' FROM '.$stats_table);
           $numwrong = $num-$Solved;
           $wrongpercent=int(10*100*$numwrong/$num)/10;
       }
       #
       # Drop the temporary table
       $dbh->do('DROP TABLE '.$stats_table);  # May return an error
       #
       # Return result
       return { num_students => $num,
                tries        => $tries,
                max_tries    => $max,
                min_tries    => $min,
                mean_tries   => $mean,
                std_tries    => $STD,
                skew_tries   => $SKEW,
                num_solved   => $Solved,
                num_override => $solved,
                num_wrong    => $numwrong,
                per_wrong    => $wrongpercent,
                deg_of_diff  => $DegOfDiff };
   }
   
     if(!defined($totalDelay)) {  ##
         $totalDelay = 10;  ## This is a helper for get_statistics
   sub execute_SQL_request {
       my ($dbh,$request)=@_;
   #    &Apache::lonnet::logthis($request);
       my $sth = $dbh->prepare($request);
       if (!$sth) {
    die($dbh->errstr . " SQL: $request");
       }
       $sth->execute();
       my $row = $sth->fetchrow_arrayref();
       if (ref($row) eq 'ARRAY' && scalar(@$row)>0) {
           return @$row;
     }      }
       return ();
   }
   
     if ((-e "$ChartDB") && (!$isRecalculate)) {  ######################################################
  $isCached = 1;  ######################################################
     } else {  
  $isCached = 0;  
     }  
   
     while($tieTries < $totalDelay) {  =pod
         my $result=0;  
         if($isCached) {  =item &populate_weight_table
             $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_READER(),0640);  
         } else {  =cut
             $result=tie(%testData,'GDBM_File',$ChartDB,&GDBM_NEWDB(),0640);  
         }  ######################################################
         if($result) {  ######################################################
             last;  sub populate_weight_table {
       my ($courseid) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       my $navmap = Apache::lonnavmaps::navmap->new();
       if (!defined($navmap)) {
           &Apache::lonnet::logthis('loncoursedata::populate_weight_table:'.$/.
                                    '  unable to get navmaps resource'.$/.
                                    '  '.join(' ',(caller)));
           return;
       }
       my @sequences = $navmap->retrieveResources(undef,
                                                  sub { shift->is_map(); },1,0,1);
       my @resources;
       foreach my $seq (@sequences) {
           push(@resources,$navmap->retrieveResources($seq,
                                                      sub {shift->is_problem();},
                                                      0,0,0));
       }
       if (! scalar(@resources)) {
           &Apache::lonnet::logthis('loncoursedata::populate_weight_table:'.$/.
                                    ' no resources returned for '.$courseid);
           return;
       }
       #       Since we use lonnet::EXT to retrieve problem weights,
       #       to ensure current data we must clear the caches out.
       &Apache::lonnet::clear_EXT_cache_status();
       my $dbh = &Apache::lonmysql::get_dbh();
       my $request = 'INSERT IGNORE INTO '.$weight_table.
           "(symb_id,part_id,weight) VALUES ";
       my $weight;
       foreach my $res (@resources) {
           my $symb_id = &get_symb_id($res->symb);
           foreach my $part (@{$res->parts}) {
               my $part_id = &get_part_id($part);
               $weight = &Apache::lonnet::EXT('resource.'.$part.'.weight',
                                              $res->symb,
                                              undef,undef,undef);
               if (!defined($weight) || ($weight eq '')) { 
                   $weight=1;
               }
               $request .= "('".$symb_id."','".$part_id."','".$weight."'),";
         }          }
         $tieTries++;  
         sleep 1;  
     }      }
     if($tieTries >= $totalDelay) {      $request =~ s/(,)$//;
         return -1;  #    &Apache::lonnet::logthis('request = '.$/.$request);
       $dbh->do($request);
       if ($dbh->err()) {
           &Apache::lonnet::logthis("error ".$dbh->errstr().
                                    " occured executing \n".
                                    $request);
     }      }
       return;
   }
   
     untie(%testData);  ##########################################################
   ##########################################################
   
     return $isCached;  =pod
 }  
   =item &limit_by_start_end_times
   
 sub DownloadStudentCourseData {  Build SQL WHERE condition which limits the data collected by the start
     my ($students,$checkDate,$cacheDB,$extract,$status,$courseID,$r,$c)=@_;  and end times provided
   
     my $title = 'LON-CAPA Statistics';  Inputs: $starttime, $endtime, $table
     my $heading = 'Download and Process Course Data';  
     my $studentCount = scalar(@$students);  
     my %cache;  
   
   Returns: $time_limits
   
     my $WhatIWant;  =cut
     $WhatIWant = '(^version:.+?$|';  
     $WhatIWant .= '^\d+:.+?:(resource\.\d+\.';  
     $WhatIWant .= '(solved|tries|previous|awarded|(\d+\.submission))\s*$';  
     $WhatIWant .= '|timestamp)';  
     $WhatIWant .= ')';  
   
     if($status eq 'true') {  ##########################################################
         &Apache::lonhtmlcommon::Create_PrgWin($r, $title, $heading);  ##########################################################
   sub limit_by_start_end_time {
       my ($starttime,$endtime,$table) = @_;
       my $time_requirements = undef;
       if (defined($starttime)) {
           $time_requirements .= $table.".timestamp>='".$starttime."'";
           if (defined($endtime)) {
               $time_requirements .= " AND ".$table.".timestamp<='".$endtime."'";
           }
       } elsif (defined($endtime)) {
           $time_requirements .= $table.".timestamp<='".$endtime."'";
     }      }
       return $time_requirements;
   }
   
     my $displayString;  ##########################################################
     my $count=0;  ##########################################################
     foreach (@$students) {  
         if($c->aborted()) { return 'Aborted'; }  
   
         if($status eq 'true') {  =pod
             $count++;  
             my $displayString = $count.'/'.$studentCount.': '.$_;  
             &Apache::lonhtmlcommon::Update_PrgWin($displayString, $r);  
         }  
   
         my $downloadTime='Not downloaded';  =item &limit_by_section_and_status
         if($checkDate eq 'true'  &&   
            tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {  
             $downloadTime = $cache{$_.':lastDownloadTime'};  
             untie(%cache);  
         }  
   
         if($c->aborted()) { return 'Aborted'; }  Build SQL WHERE condition which limits the data collected by section and
   student status.
   
         if($downloadTime eq 'Not downloaded') {  Inputs: $Sections (array ref)
             my $courseData =       $enrollment (string: 'any', 'expired', 'active')
                 &DownloadCourseInformation($_, $courseID, $downloadTime,       $tablename The name of the table that holds the student data
                                            $WhatIWant);  
             if(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {  Returns: $student_requirements,$enrollment_requirements
                 foreach my $key (keys(%$courseData)) {  
                     if($key =~ /^(con_lost|error|no_such_host)/i) {  =cut
                         $courseData->{$_.':error'} = 'No course data for '.$_;  
                         last;  ##########################################################
                     }  ##########################################################
                 }  sub limit_by_section_and_status {
                 if($extract eq 'true') {      my ($Sections,$enrollment,$tablename) = @_;
                     &ExtractStudentData($courseData, \%cache, \%cache, $_);      my $student_requirements = undef;
                 } else {      if ( (defined($Sections) && $Sections->[0] ne 'all')) {
                     &ProcessStudentData(\%cache, $courseData, $_);          $student_requirements = '('.
                 }              join(' OR ', map { $tablename.".section='".$_."'" } @$Sections
                 untie(%cache);                   ).')';
             } else {      }
                 next;      #
             }      my $enrollment_requirements=undef;
         }      if (defined($enrollment) && $enrollment ne 'Any') {
           $enrollment_requirements = $tablename.".status='".$enrollment."'";
     }      }
     if($status eq 'true') { &Apache::lonhtmlcommon::Close_PrgWin($r); }      return ($student_requirements,$enrollment_requirements);
   }
   
   ######################################################
   ######################################################
   
   =pod
   
     return 'OK';  =item rank_students_by_scores_on_resources
   
   Inputs: 
       $resources: array ref of hash ref.  Each hash ref needs key 'symb'.
       $Sections: array ref of sections to include,
       $enrollment: string,
       $courseid (may be omitted)
       $starttime (may be omitted)
       $endtime (may be omitted)
       $has_award_for (may be omitted)
   
   Returns; An array of arrays.  The sub arrays contain a student name and
   their score on the resources. $starttime and $endtime constrain the
   list to awards obtained during the given time limits. $has_score_on
   constrains the list to those students who at least attempted the
   resource identified by the given symb, which is used to filter out
   such students for statistics that would be adversely affected by such
   students. 
   
   =cut
   
   ######################################################
   ######################################################
   sub RNK_student { return 0; };
   sub RNK_score   { return 1; };
   
   sub rank_students_by_scores_on_resources {
       my ($resources,$Sections,$enrollment,$courseid,$starttime,$endtime,$has_award_for) = @_;
       return if (! defined($resources) || ! ref($resources) eq 'ARRAY');
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       my ($section_limits,$enrollment_limits)=
           &limit_by_section_and_status($Sections,$enrollment,'b');
       my $symb_limits = '('.join(' OR ',map {'a.symb_id='.&get_symb_id($_);
                                          } @$resources
                                  ).')';
       my ($award_col, $award_join, $award_clause) = ('', '', '');
       if ($has_award_for) {
           my $resource_id = &get_symb_id($has_award_for);
           $award_col = ", perf.awarded";
           $award_join = "LEFT JOIN $performance_table AS perf ON perf.symb_id"
               ." = $resource_id AND perf.student_id = b.student_id ";
           $award_clause = "AND perf.awarded IS NOT NULL";
       }
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my $request = "SELECT b.student,SUM(a.awarded*w.weight) AS score "
           ."$award_col FROM $performance_table AS a ".
           "NATURAL LEFT JOIN $weight_table AS w ".
           "LEFT JOIN $student_table AS b ON a.student_id=b.student_id ".
           "$award_join WHERE ";
       if (defined($section_limits)) {
           $request .= $section_limits.' AND ';
       }
       if (defined($enrollment_limits)) {
           $request .= $enrollment_limits.' AND ';
       }
       if (defined($time_limits)) {
           $request .= $time_limits.' AND ';
       }
       if ($symb_limits ne '()') {
           $request .= $symb_limits.' AND ';
       }
       $request =~ s/( AND )$//;   # Remove extra conjunction
       $request =~ s/( WHERE )$//; # In case there were no limits placed on it
       $request .= " $award_clause GROUP BY a.student_id ORDER BY score";
       #&Apache::lonnet::logthis('request = '.$/.$request);
       my $sth = $dbh->prepare($request) or die "Can't prepare $request";
       $sth->execute();
       my $rows = $sth->fetchall_arrayref();
       return ($rows);
 }  }
   
 sub DownloadStudentCourseDataSeparate {  ########################################################
     my ($students,$checkDate,$cacheDB,$extract,$status,$courseID,$r,$c)=@_;  ########################################################
     my $residualFile = '/home/httpd/perl/tmp/'.$courseID.'DownloadFile.db';  
     my $title = 'LON-CAPA Statistics';  =pod
     my $heading = 'Download Course Data';  
   =item &get_sum_of_scores
   
 #    my $WhatIWant = '.';  Inputs: $resource (hash ref, needs {'symb'} key),
     my $WhatIWant;  $part, (the part id),
     $WhatIWant = '(^version:.+?$|';  $students (array ref, contents of array are scalars holding 'sname:sdom'),
     $WhatIWant .= '^\d+:.+?:(resource\.\d+\.';  $courseid
     $WhatIWant .= '(solved|tries|previous|awarded|(\d+\.submission))\s*$';  
     $WhatIWant .= '|timestamp)';  
     $WhatIWant .= ')';  
   
     &CheckForResidualDownload($courseID, $cacheDB, $students, $c);  Returns: the sum of the score on the problem part over the students and the
      maximum possible value for the sum (taken from the weight table).
   
     my %cache;  =cut
   
     my $studentCount = scalar(@$students);  ########################################################
     if($status eq 'true') {  ########################################################
         &Apache::lonhtmlcommon::Create_PrgWin($r, $title, $heading);  sub get_sum_of_scores {
       my ($symb,$part,$students,$courseid,$starttime,$endtime) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       if (defined($students) && 
           ((@$students == 0) ||
            (@$students == 1 && (! defined($students->[0]) || 
                                 $students->[0] eq ''))
            )
           ){
           undef($students);
       }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my $request = 'SELECT SUM(a.awarded*w.weight),SUM(w.weight) FROM '.
           $performance_table.' AS a '.
           'NATURAL LEFT JOIN '.$weight_table.' AS w ';
       $request .= 'WHERE a.symb_id='.&get_symb_id($symb).
           ' AND a.part_id='.&get_part_id($part);
       if (defined($time_limits)) {
           $request .= ' AND '.$time_limits;
       }
       if (defined($students)) {
           $request .= ' AND ('.
               join(' OR ',map {'a.student_id='.&get_student_id(split(':',$_));
                            } @$students).
                                ')';
       }
       my $sth = $dbh->prepare($request);
       $sth->execute();
       my $rows = $sth->fetchrow_arrayref();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 1 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed, fetchrow_arrayrefed'.
                                    $/.$request);
           return (undef,undef);
     }      }
     my $count=0;      return ($rows->[0],$rows->[1]);
     my $displayString='';  }
     foreach (@$students) {  
         if($c->aborted()) {  
             return 'Aborted';  
         }  
   
         if($status eq 'true') {  ########################################################
             $count++;  ########################################################
             $displayString = $count.'/'.$studentCount.': '.$_;  
             &Apache::lonhtmlcommon::Update_PrgWin($displayString, $r);  
         }  
   
         my $downloadTime='Not downloaded';  =pod
         if($checkDate eq 'true'  &&   
            tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {  
             $downloadTime = $cache{$_.':lastDownloadTime'};  
             untie(%cache);  
         }  
   
         if($c->aborted()) {  =item &score_stats
             return 'Aborted';  
         }  
   
         if($downloadTime eq 'Not downloaded') {  Inputs: $Sections, $enrollment, $symbs, $starttime,
             my $error = 0;          $endtime, $courseid
             my $courseData =   
                 &DownloadCourseInformation($_, $courseID, $downloadTime,  $Sections, $enrollment, $starttime, $endtime, and $courseid are the same as 
                                            $WhatIWant);  elsewhere in this module.  
             my %downloadData;  $symbs is an array ref of symbs
             unless(tie(%downloadData,'GDBM_File',$residualFile,  
                        &GDBM_WRCREAT(),0640)) {  Returns: minimum, maximum, mean, s.d., number of students, and maximum
                 return 'Failed to tie temporary download hash.';    possible of student scores on the given resources
             }  
             foreach my $key (keys(%$courseData)) {  
                 $downloadData{$key} = $courseData->{$key};  
                 if($key =~ /^(con_lost|error|no_such_host)/i) {  
                     $error = 1;  
                     last;  
                 }  
             }  
             if($error) {  
                 foreach my $deleteKey (keys(%$courseData)) {  
                     delete $downloadData{$deleteKey};  
                 }  
                 $downloadData{$_.':error'} = 'No course data for '.$_;  
             }  
             untie(%downloadData);  
         }  
     }  
     if($status eq 'true') { &Apache::lonhtmlcommon::Close_PrgWin($r); }  
   
     return &CheckForResidualDownload($cacheDB, 'true', 'true',   =cut
                                      $courseID, $r, $c);  
   ########################################################
   ########################################################
   sub score_stats {
       my ($Sections,$enrollment,$symbs,$starttime,$endtime,$courseid)=@_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       #
       my ($section_limits,$enrollment_limits)=
           &limit_by_section_and_status($Sections,$enrollment,'b');
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my @Symbids = map { &get_symb_id($_); } @{$symbs};
       #
       my $stats_table = $courseid.'_problem_stats';
       my $symb_restriction = join(' OR ',map {'a.symb_id='.$_;} @Symbids);
       my $request = 'DROP TABLE '.$stats_table;
       $dbh->do($request);
       $request = 
           'CREATE TEMPORARY TABLE '.$stats_table.' '.
           'SELECT a.student_id,'.
           'SUM(a.awarded*w.weight) AS score FROM '.
           $performance_table.' AS a '.
           'NATURAL LEFT JOIN '.$weight_table.' AS w '.
           'LEFT JOIN '.$student_table.' AS b ON a.student_id=b.student_id '.
           'WHERE ('.$symb_restriction.')';
       if ($time_limits) {
           $request .= ' AND '.$time_limits;
       }
       if ($section_limits) {
           $request .= ' AND '.$section_limits;
       }
       if ($enrollment_limits) {
           $request .= ' AND '.$enrollment_limits;
       }
       $request .= ' GROUP BY a.student_id';
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       $request = 
           'SELECT AVG(score),STD(score),MAX(score),MIN(score),COUNT(score) '.
           'FROM '.$stats_table;
       my ($ave,$std,$max,$min,$count) = &execute_SQL_request($dbh,$request);
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       
       $request = 'SELECT SUM(weight) FROM '.$weight_table.
           ' AS a WHERE ('.$symb_restriction.')';
       my ($max_possible) = &execute_SQL_request($dbh,$request);
       # &Apache::lonnet::logthis('request = '.$/.$request);
       return($min,$max,$ave,$std,$count,$max_possible);
 }  }
   
 sub CheckForResidualDownload {  
     my ($cacheDB,$extract,$status,$courseID,$r,$c)=@_;  
   
     my $residualFile = '/home/httpd/perl/tmp/'.$courseID.'DownloadFile.db';  ########################################################
     if(!-e $residualFile) {  ########################################################
         return 'OK';  
     }  =pod
   
     my %downloadData;  =item &count_stats
     my %cache;  
     unless(tie(%downloadData,'GDBM_File',$residualFile,&GDBM_READER(),0640)) {  Inputs: $Sections, $enrollment, $symbs, $starttime,
         return 'Can not tie database for check for residual download: tempDB';          $endtime, $courseid
   
   $Sections, $enrollment, $starttime, $endtime, and $courseid are the same as 
   elsewhere in this module.  
   $symbs is an array ref of symbs
   
   Returns: minimum, maximum, mean, s.d., and number of students
     of the number of items correct on the given resources
   
   =cut
   
   ########################################################
   ########################################################
   sub count_stats {
       my ($Sections,$enrollment,$symbs,$starttime,$endtime,$courseid)=@_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       #
       my ($section_limits,$enrollment_limits)=
           &limit_by_section_and_status($Sections,$enrollment,'b');
       my $time_limits = &limit_by_start_end_time($starttime,$endtime,'a');
       my @Symbids = map { &get_symb_id($_); } @{$symbs};
       #
       my $stats_table = $courseid.'_problem_stats';
       my $symb_restriction = join(' OR ',map {'a.symb_id='.$_;} @Symbids);
       my $request = 'DROP TABLE '.$stats_table;
       $dbh->do($request);
       $request = 
           'CREATE TEMPORARY TABLE '.$stats_table.' '.
           'SELECT a.student_id,'.
           'SUM(a.awarded) AS count FROM '.
           $performance_table.' AS a '.
           'LEFT JOIN '.$student_table.' AS b ON a.student_id=b.student_id '.
           'WHERE ('.$symb_restriction.')';
       if ($time_limits) {
           $request .= ' AND '.$time_limits;
       }
       if ($section_limits) {
           $request .= ' AND '.$section_limits;
       }
       if ($enrollment_limits) {
           $request .= ' AND '.$enrollment_limits;
       }
       $request .= ' GROUP BY a.student_id';
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       $request = 
           'SELECT AVG(count),STD(count),MAX(count),MIN(count),COUNT(count) '.
           'FROM '.$stats_table;
       my ($ave,$std,$max,$min,$count) = &execute_SQL_request($dbh,$request);
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       return($min,$max,$ave,$std,$count);
   }
   
   ######################################################
   ######################################################
   
   =pod
   
   =item get_student_data
   
   =cut
   
   ######################################################
   ######################################################
   sub get_student_data {
       my ($students,$courseid) = @_;
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       my $request = 'SELECT '.
           'student_id, student '.
           'FROM '.$student_table;
       if (defined($students)) {
           $request .= ' WHERE ('.
               join(' OR ', map {'student_id='.
                                     &get_student_id($_->{'username'},
                                                     $_->{'domain'})
                                 } @$students
                    ).')';
       }
       $request.= ' ORDER BY student_id';
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 2 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           return $dataset;
     }      }
     unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {  }
         untie(%downloadData);  
         return 'Can not tie database for check for residual download: cacheDB';  sub RD_student_id      { return 0; }
   sub RD_awarddetail     { return 1; }
   sub RD_response_eval   { return 2; }
   sub RD_response_eval_2 { return 3; }
   sub RD_submission      { return 4; }
   sub RD_timestamp       { return 5; }
   sub RD_tries           { return 6; }
   sub RD_sname           { return 7; }
   
   sub get_response_data {
       my ($Sections,$enrollment,$symb,$response,$courseid) = @_;
       return undef if (! defined($symb) || 
                  ! defined($response));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       if (! defined($symb_id)) {
           &Apache::lonnet::logthis('Unable to find symb for '.$symb.' in '.$courseid);
           return undef;
       }
       my $response_id = &get_part_id($response);
       if (! defined($response_id)) {
           &Apache::lonnet::logthis('Unable to find id for '.$response.' in '.$courseid);
           return undef;
       }
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       #
       my ($student_requirements,$enrollment_requirements) = 
           &limit_by_section_and_status($Sections,$enrollment,'d');
       my $request = 'SELECT '.
           'a.student_id, a.awarddetail, a.response_specific_value, '.
           'a.response_specific_value_2, a.submission, b.timestamp, '.
    'c.tries, d.student '.
           'FROM '.$fulldump_response_table.' AS a '.
           'LEFT JOIN '.$fulldump_timestamp_table.' AS b '.
           'ON a.symb_id=b.symb_id AND a.student_id=b.student_id AND '.
           'a.transaction = b.transaction '.
           'LEFT JOIN '.$fulldump_part_table.' AS c '.
           'ON a.symb_id=c.symb_id AND a.student_id=c.student_id AND '.        
           'a.part_id=c.part_id AND a.transaction = c.transaction '.
           'LEFT JOIN '.$student_table.' AS d '.
           'ON a.student_id=d.student_id '.
           'WHERE '.
           'a.symb_id='.$symb_id.' AND a.response_id='.$response_id;
       if (defined($student_requirements) || defined($enrollment_requirements)) {
           $request .= ' AND ';
           if (defined($student_requirements)) {
               $request .= $student_requirements.' AND ';
           }
           if (defined($enrollment_requirements)) {
               $request .= $enrollment_requirements.' AND ';
           }
           $request =~ s/( AND )$//;
       }
       $request .= ' ORDER BY b.timestamp';
   #    &Apache::lonnet::logthis("request =\n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 3 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           # Clear the \'s from around the submission
           for (my $i =0;$i<scalar(@$dataset);$i++) {
               $dataset->[$i]->[3] =~ s/(\'$|^\')//g;
           }
           return $dataset;
     }      }
   }
   
     my @students=();  
     my %checkStudent;  sub RDs_awarddetail     { return 3; }
     my $key;  sub RDs_submission      { return 2; }
     while(($key, undef) = each %downloadData) {  sub RDs_timestamp       { return 1; }
         my @temp = split(':', $key);  sub RDs_tries           { return 0; }
         my $student = $temp[0].':'.$temp[1];  sub RDs_awarded         { return 4; }
         if(!defined($checkStudent{$student})) {  sub RDs_response_eval   { return 5; }
             $checkStudent{$student}++;  sub RDs_response_eval_2 { return 6; }
             push(@students, $student);  sub RDs_part_award      { return 7; }
   
   sub get_response_data_by_student {
       my ($student,$symb,$response,$courseid) = @_;
       return undef if (! defined($symb) || 
                        ! defined($response));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       my $response_id = &get_part_id($response);
       #
       my $student_id = &get_student_id($student->{'username'},
                                        $student->{'domain'});
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       my $request = 'SELECT '.
           'c.tries, b.timestamp, a.submission, a.awarddetail, c.awarded, '.
    'a.response_specific_value, a.response_specific_value_2, c.award '.
           'FROM '.$fulldump_response_table.' AS a '.
           'LEFT JOIN '.$fulldump_timestamp_table.' AS b '.
           'ON a.symb_id=b.symb_id AND a.student_id=b.student_id AND '.
           'a.transaction = b.transaction '.
           'LEFT JOIN '.$fulldump_part_table.' AS c '.
           'ON a.symb_id=c.symb_id AND a.student_id=c.student_id AND '.        
           'a.part_id=c.part_id AND a.transaction = c.transaction '.
           'LEFT JOIN '.$student_table.' AS d '.
           'ON a.student_id=d.student_id '.
           'LEFT JOIN '.$performance_table.' AS e '.
           'ON a.symb_id=e.symb_id AND a.part_id=e.part_id AND '.
           'a.student_id=e.student_id AND c.tries=e.tries '.
           'WHERE '.
           'a.symb_id='.$symb_id.' AND a.response_id='.$response_id.
           ' AND a.student_id='.$student_id.' ORDER BY b.timestamp';
   #    &Apache::lonnet::logthis("request =\n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 4 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           # Clear the \'s from around the submission
           for (my $i =0;$i<scalar(@$dataset);$i++) {
               $dataset->[$i]->[2] =~ s/(\'$|^\')//g;
         }          }
           return $dataset;
     }      }
       return undef; # error occurred
   }
   
     my $heading = 'Process Course Data';  sub RT_student_id { return 0; }
     my $title = 'LON-CAPA Statistics';  sub RT_awarded    { return 1; }
     my $studentCount = scalar(@students);  sub RT_tries      { return 2; }
     if($status eq 'true') {  sub RT_timestamp  { return 3; }
         &Apache::lonhtmlcommon::Create_PrgWin($r, $title, $heading);  
   sub get_response_time_data {
       my ($sections,$enrollment,$symb,$part,$courseid) = @_;
       return undef if (! defined($symb) || 
                        ! defined($part));
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       #
       &setup_table_names($courseid);
       my $symb_id = &get_symb_id($symb);
       if (! defined($symb_id)) {
           &Apache::lonnet::logthis('Unable to find symb for '.$symb.' in '.$courseid);
           return undef;
       }
       my $part_id = &get_part_id($part);
       if (! defined($part_id)) {
           &Apache::lonnet::logthis('Unable to find id for '.$part.' in '.$courseid);
           return undef;
       }
       #
       my $dbh = &Apache::lonmysql::get_dbh();
       return undef if (! defined($dbh));
       my ($student_requirements,$enrollment_requirements) = 
           &limit_by_section_and_status($sections,$enrollment,'d');
       my $request = 'SELECT '.
           'a.student_id, a.awarded, a.tries, b.timestamp '.
           'FROM '.$fulldump_part_table.' AS a '.
           'LEFT JOIN '.$fulldump_timestamp_table.' AS b '.
           'ON a.symb_id=b.symb_id AND a.student_id=b.student_id AND '.
           'a.transaction = b.transaction '.
           'LEFT JOIN '.$student_table.' as d '.
           'ON a.student_id=d.student_id '.
           'WHERE '.
           'a.symb_id='.$symb_id.' AND a.part_id='.$part_id;
       if (defined($student_requirements) || defined($enrollment_requirements)) {
           $request .= ' AND ';
           if (defined($student_requirements)) {
               $request .= $student_requirements.' AND ';
           }
           if (defined($enrollment_requirements)) {
               $request .= $enrollment_requirements.' AND ';
           }
           $request =~ s/( AND )$//;
       }
       $request .= ' ORDER BY b.timestamp';
   #    &Apache::lonnet::logthis("request =\n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 5 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       my $dataset = $sth->fetchall_arrayref();
       if (ref($dataset) eq 'ARRAY' && scalar(@$dataset)>0) {
           return $dataset;
     }      }
   
     my $count=1;  }
     foreach my $name (@students) {  
         last if($c->aborted());  
   
         if($status eq 'true') {  ################################################
             my $displayString = $count.'/'.$studentCount.': '.$_;  ################################################
             &Apache::lonhtmlcommon::Update_PrgWin($displayString, $r);  
         }  
   
         if($extract eq 'true') {  =pod
             &ExtractStudentData(\%downloadData, \%cache, \%cache, $name);  
         } else {  
             &ProcessStudentData(\%cache, \%downloadData, $name);  
         }  
         $count++;  
     }  
   
     if($status eq 'true') { &Apache::lonhtmlcommon::Close_PrgWin($r); }  =item &get_student_scores($Sections,$Symbs,$enrollment,$courseid)
   
     untie(%cache);  =cut
     untie(%downloadData);  
   
     if(!$c->aborted()) {  ################################################
         my @files = ($residualFile);  ################################################
         unlink(@files);  sub get_student_scores {
       my ($sections,$Symbs,$enrollment,$courseid,$starttime,$endtime) = @_;
       $courseid = $env{'request.course.id'} if (! defined($courseid));
       &setup_table_names($courseid);
       my $dbh = &Apache::lonmysql::get_dbh();
       return (undef) if (! defined($dbh));
       my $tmptable = $courseid.'_temp_'.time;
       my $request = 'DROP TABLE IF EXISTS '.$tmptable;
   #    &Apache::lonnet::logthis('request = '.$/.$request);
       $dbh->do($request);
       #
       my $symb_requirements;
       if (defined($Symbs)  && @$Symbs) {
           $symb_requirements = '('.
               join(' OR ', map{ "(a.symb_id='".&get_symb_id($_->{'symb'}).
                                 "' AND a.part_id='".&get_part_id($_->{'part'}).
                                 "')"
                                 } @$Symbs).')';
       }
       #
       my ($student_requirements,$enrollment_requirements) = 
           &limit_by_section_and_status($sections,$enrollment,'b');
       #
       my $time_requirements = &limit_by_start_end_time($starttime,$endtime,'a');
       ##
       $request = 'CREATE TEMPORARY TABLE IF NOT EXISTS '.$tmptable.
           ' SELECT a.student_id,SUM(a.awarded*c.weight) AS score FROM '.
           $performance_table.' AS a ';
       $request .= "LEFT JOIN ".$weight_table.' AS c ON a.symb_id=c.symb_id AND a.part_id=c.part_id ';
       if (defined($student_requirements) || defined($enrollment_requirements)) {
           $request .= ' LEFT JOIN '.$student_table.' AS b ON a.student_id=b.student_id';
       }
       if (defined($symb_requirements)      || 
           defined($student_requirements)   ||
           defined($enrollment_requirements) ) {
           $request .= ' WHERE ';
       }
       if (defined($symb_requirements)) {
           $request .= $symb_requirements.' AND ';
       }
       if (defined($student_requirements)) {
           $request .= $student_requirements.' AND ';
       }
       if (defined($enrollment_requirements)) {
           $request .= $enrollment_requirements.' AND ';
       }
       if (defined($time_requirements)) {
           $request .= $time_requirements.' AND ';
       }
       $request =~ s/ AND $//; # Strip of the trailing ' AND '.
       $request .= ' GROUP BY a.student_id';
   #    &Apache::lonnet::logthis("request = \n".$request);
       my $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 6 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
       }
       $request = 'SELECT score,COUNT(*) FROM '.$tmptable.' GROUP BY score';
   #    &Apache::lonnet::logthis("request = \n".$request);
       $sth = $dbh->prepare($request);
       $sth->execute();
       if ($dbh->err) {
           &Apache::lonnet::logthis('error 7 = '.$dbh->errstr());
           &Apache::lonnet::logthis('prepared then executed '.$/.$request);
           return undef;
     }      }
       my $dataset = $sth->fetchall_arrayref();
       return $dataset;
   }
   
   ################################################
   ################################################
   
   =pod
   
   =item &setup_table_names()
   
   input: course id
   
     return 'OK';  output: none
   
   Cleans up the package variables for local caching.
   
   =cut
   
   ################################################
   ################################################
   sub setup_table_names {
       my ($courseid) = @_;
       if (! defined($courseid)) {
           $courseid = $env{'request.course.id'};
       }
       #
       if (! defined($current_course) || $current_course ne $courseid) {
           # Clear out variables
           $have_read_part_table = 0;
           undef(%ids_by_part);
           undef(%parts_by_id);
           $have_read_symb_table = 0;
           undef(%ids_by_symb);
           undef(%symbs_by_id);
           $have_read_student_table = 0;
           undef(%ids_by_student);
           undef(%students_by_id);
           #
           $current_course = $courseid;
       }
       #
       # Set up database names
       my $base_id = $courseid;
       $symb_table        = $base_id.'_'.'symb';
       $part_table        = $base_id.'_'.'part';
       $student_table     = $base_id.'_'.'student';
       $performance_table = $base_id.'_'.'performance';
       $parameters_table  = $base_id.'_'.'parameters';
       $fulldump_part_table      = $base_id.'_'.'partdata';
       $fulldump_response_table  = $base_id.'_'.'responsedata';
       $fulldump_timestamp_table = $base_id.'_'.'timestampdata';
       $weight_table             = $base_id.'_'.'weight';
       #
       @Tables = (
                  $symb_table,
                  $part_table,
                  $student_table,
                  $performance_table,
                  $parameters_table,
                  $fulldump_part_table,
                  $fulldump_response_table,
                  $fulldump_timestamp_table,
                  $weight_table,
                  );
       return;
 }  }
   
 sub GetFileTimestamp {  ################################################
     my ($studentDomain,$studentName,$filename,$root)=@_;  ################################################
     $studentDomain=~s/\W//g;  
     $studentName=~s/\W//g;  =pod
     my $subdir=$studentName.'__';  
     $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;  =back
     my $proname="$studentDomain/$subdir/$studentName";  
     $proname .= '/'.$filename;  =item End of Local Data Caching Subroutines
     my @dir = &Apache::lonnet::dirlist($proname, $studentDomain, $studentName,  
                                        $root);  =cut
     my $fileStat = $dir[0];  
     my @stats = split('&', $fileStat);  ################################################
     if($stats[0] ne 'empty' && $stats[0] ne 'no_such_dir') {  ################################################
         return $stats[9];  
   } # End scope of table identifiers
   
   ################################################
   ################################################
   
   =pod
   
   =head3 Classlist Subroutines
   
   =item &get_classlist();
   
   Retrieve the classist of a given class or of the current class.  Student
   information is returned from the classlist.db file and, if needed,
   from the students environment.
   
   Optional arguments are $cdom, and $cnum (course domain,
   and course number, respectively).  If either is ommitted the course
   will be taken from the current environment ($env{'request.course.id'},
   $env{'course.'.$cid.'.domain'}, and $env{'course.'.$cid.'.num'}).
   
   Returns a reference to a hash which contains:
    keys    '$sname:$sdom'
    values  [$sdom,$sname,$end,$start,$id,$section,$fullname,$status,$type,$lockedtype]
   
   The constant values CL_SDOM, CL_SNAME, CL_END, etc. can be used
   as indices into the returned list to future-proof clients against
   changes in the list order.
   
   =cut
   
   ################################################
   ################################################
   
   sub CL_SDOM     { return 0; }
   sub CL_SNAME    { return 1; }
   sub CL_END      { return 2; }
   sub CL_START    { return 3; }
   sub CL_ID       { return 4; }
   sub CL_SECTION  { return 5; }
   sub CL_FULLNAME { return 6; }
   sub CL_STATUS   { return 7; }
   sub CL_TYPE     { return 8; }
   sub CL_LOCKEDTYPE   { return 9; }
   
   sub get_classlist {
       my ($cdom,$cnum) = @_;
       my $cid = $cdom.'_'.$cnum;
       if (!defined($cdom) || !defined($cnum)) {
    $cid =  $env{'request.course.id'};
    $cdom = $env{'course.'.$cid.'.domain'};
    $cnum = $env{'course.'.$cid.'.num'};
       }
       my $now = time;
       #
       my %classlist=&Apache::lonnet::dump('classlist',$cdom,$cnum);
       while (my ($student,$info) = each(%classlist)) {
           if ($student =~ /^(con_lost|error|no_such_host)/i) {
               &Apache::lonnet::logthis('get_classlist error for '.$cid.':'.$student);
               return undef;
           }
           my ($sname,$sdom) = split(/:/,$student);
           my @Values = split(/:/,$info);
           my ($end,$start,$id,$section,$fullname,$type,$lockedtype);
           if (@Values > 2) {
               ($end,$start,$id,$section,$fullname,$type,$lockedtype) = @Values;
           } else { # We have to get the data ourselves
               ($end,$start) = @Values;
               $section = &Apache::lonnet::getsection($sdom,$sname,$cid);
               my %info=&Apache::lonnet::get('environment',
                                             ['firstname','middlename',
                                              'lastname','generation','id'],
                                             $sdom, $sname);
               my ($tmp) = keys(%info);
               if ($tmp =~/^(con_lost|error|no_such_host)/i) {
                   $fullname = 'not available';
                   $id = 'not available';
                   &Apache::lonnet::logthis('unable to retrieve environment '.
                                            'for '.$sname.':'.$sdom);
               } else {
                   $fullname = &Apache::lonnet::format_name(@info{qw/firstname middlename lastname generation/},'lastname');
                   $id = $info{'id'};
               }
               # Update the classlist with this students information
               if ($fullname ne 'not available') {
    my $enrolldata = join(':',$end,$start,$id,$section,$fullname);
    my $reply=&Apache::lonnet::cput('classlist',
                                                   {$student => $enrolldata},
                                                   $cdom,$cnum);
                   if ($reply !~ /^(ok|delayed)/) {
                       &Apache::lonnet::logthis('Unable to update classlist for '.
                                                'student '.$sname.':'.$sdom.
                                                ' error:'.$reply);
                   }
               }
           }
           my $status='Expired';
           if(((!$end) || $now < $end) && ((!$start) || ($now > $start))) {
               $status='Active';
           }
           $classlist{$student} = 
               [$sdom,$sname,$end,$start,$id,$section,$fullname,$status,$type,$lockedtype];
       }
       if (wantarray()) {
           return (\%classlist,['domain','username','end','start','id',
                                'section','fullname','status','type','lockedtype']);
     } else {      } else {
         return -1;          return \%classlist;
     }      }
 }  }
   
Line 1240  sub GetFileTimestamp { Line 2812  sub GetFileTimestamp {
   
 1;  1;
 __END__  __END__
   
   

Removed from v.1.18  
changed lines
  Added in v.1.162


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