--- loncom/interface/loncoursedata.pm	2005/11/11 23:23:24	1.151
+++ loncom/interface/loncoursedata.pm	2006/03/04 06:11:08	1.156
@@ -1,6 +1,6 @@
 # The LearningOnline Network with CAPA
 #
-# $Id: loncoursedata.pm,v 1.151 2005/11/11 23:23:24 albertel Exp $
+# $Id: loncoursedata.pm,v 1.156 2006/03/04 06:11:08 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -66,30 +66,6 @@ and/or itself.
 
 =cut
 
-sub LoadDiscussion {
-    my ($courseID)=@_;
-    my %Discuss=();
-    my %contrib=&Apache::lonnet::dump(
-                $courseID,
-                $env{'course.'.$courseID.'.domain'},
-                $env{'course.'.$courseID.'.num'});
-				 
-    #my %contrib=&DownloadCourseInformation($name, $courseID, 0);
-
-    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;
-}
-
 ################################################
 ################################################
 
@@ -1873,6 +1849,9 @@ 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) {
@@ -2030,9 +2009,17 @@ Inputs:
     $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.
+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
 
@@ -2042,7 +2029,7 @@ sub RNK_student { return 0; };
 sub RNK_score   { return 1; };
 
 sub rank_students_by_scores_on_resources {
-    my ($resources,$Sections,$enrollment,$courseid,$starttime,$endtime) = @_;
+    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'};
@@ -2055,12 +2042,20 @@ sub rank_students_by_scores_on_resources
     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 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 ';
+    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 ';
     }
@@ -2075,9 +2070,9 @@ sub rank_students_by_scores_on_resources
     }
     $request =~ s/( AND )$//;   # Remove extra conjunction
     $request =~ s/( WHERE )$//; # In case there were no limits placed on it
-    $request .= ' GROUP BY a.student_id ORDER BY score';
+    $request .= " $award_clause GROUP BY a.student_id ORDER BY score";
     #&Apache::lonnet::logthis('request = '.$/.$request);
-    my $sth = $dbh->prepare($request);
+    my $sth = $dbh->prepare($request) or die "Can't prepare $request";
     $sth->execute();
     my $rows = $sth->fetchall_arrayref();
     return ($rows);
@@ -2212,7 +2207,7 @@ sub score_stats {
 #    &Apache::lonnet::logthis('request = '.$/.$request);
     
     $request = 'SELECT SUM(weight) FROM '.$weight_table.
-        ' WHERE ('.$symb_restriction.')';
+        ' AS a WHERE ('.$symb_restriction.')';
     my ($max_possible) = &execute_SQL_request($dbh,$request);
     # &Apache::lonnet::logthis('request = '.$/.$request);
     return($min,$max,$ave,$std,$count,$max_possible);