deletion of the column added

darcs-hash:20101217061736-067c0-840e7635108a0a2af5cd95d9b9bd0ab749ec123c.gz

1 files changed, 39 insertions, 2 deletions

diff --git a/GradeBook.tcl b/GradeBook.tcl
index ed845f5..70b7873 100755
--- a/GradeBook.tcl
+++ b/GradeBook.tcl
@@ -118,7 +118,7 @@ proc htmlDBout {db permission_list {sort_col {}}} {
 						foreach {act act_label} $action_list {
 							if { [info exist permission($act) ] } {
 								if { $permission($act) } {
-									puts -nonewline "$separator<a href=$script_name?action=$act>$act_label</a>"
+									puts -nonewline "$separator<a href=$script_name?action=$act&columnname=[::ncgi::encode $col]>$act_label</a>"
 								}
 							} 
 						}
@@ -252,7 +252,10 @@ proc ChoseAction {action permission_list user} {
 				           htmlDefaultView    $permission_list  $user
 					 } 
 			addcolumnrequest { AddColumnRequest   $permission_list  $user } 
-			deletecolumn     { } 
+			deletecolumn     { 
+			                   DeleteColumn       $permission_list  $user;
+				           htmlDefaultView    $permission_list  $user
+			                 } 
 			renamecolumn     { } 
 			showcontrols     { ShowControls       $permission_list  $user } 
 			showgrades       { htmlGradesTable db $permission_list  $user }
@@ -262,6 +265,40 @@ proc ChoseAction {action permission_list user} {
 	} 
 }
 
+proc DeleteColumn { permission_list user } {
+	global script_name
+	set columnname [::ncgi::value columnname {}]
+	if { $columnname != "" } {
+		set eval_str [concat SELECT * FROM GradesTable ]
+		set err [catch {db eval $eval_str v {} } errStat]
+		set old_column_list $v(*)
+		# removing the column name to be deleted from total list
+		set new_column_list {}
+		foreach cname $old_column_list {
+			if { $cname ne $columnname } {
+				lappend new_column_list \"$cname\"
+			}
+		}
+		set sql_new_column_list [join $new_column_list ","]
+		set eval_str "BEGIN TRANSACTION;
+			CREATE TEMPORARY TABLE GradesTable_backup($sql_new_column_list);
+			INSERT INTO GradesTable_backup SELECT $sql_new_column_list FROM GradesTable;
+			DROP TABLE GradesTable;
+			CREATE TABLE GradesTable($sql_new_column_list);
+			INSERT INTO GradesTable SELECT $sql_new_column_list FROM GradesTable_backup;
+			DROP TABLE GradesTable_backup;
+			COMMIT;"
+		set err [catch {db eval $eval_str  } errStat]
+		if { $err } {
+			puts "the following error happen: $errStat"
+			dbg  "the following error happen: $errStat" 3
+		} 
+	} else {
+		puts "error: empty column names are not permitted"
+	}
+}
+
+
 proc AddColumn { permission_list user } { 
 	global script_name
 	set columnname2add [::ncgi::value columnname2add {}]