Bug 347439: Implement support for referential integrity in Bugzilla::DB::Schema…

Bugzilla/DB.pm

@@ -515,10 +515,11 @@ sub bz_alter_column_raw {
     my @statements = $self->_bz_real_schema->get_alter_column_ddl(
         $table, $name, $new_def,
         defined $set_nulls_to ? $self->quote($set_nulls_to) : undef);
-    my $new_ddl = $self->_bz_schema->get_type_ddl($new_def);
+    my $new_ddl = $self->_bz_schema->get_display_ddl($table, $name, $new_def);
     print "Updating column $name in table $table ...\n";
     if (defined $current_def) {
-        my $old_ddl = $self->_bz_schema->get_type_ddl($current_def);
+        my $old_ddl = $self->_bz_schema->get_display_ddl($table, $name, 
+                                                         $current_def);
         print "Old: $old_ddl\n";
     }
     print "New: $new_ddl\n";

Bugzilla/DB/Schema/Mysql.pm

@@ -176,9 +176,17 @@ sub get_alter_column_ddl {
         # keys are not allowed.
         delete $new_def_copy{PRIMARYKEY};
     }
+    # CHANGE COLUMN doesn't support REFERENCES
+    delete $new_def_copy{REFERENCES};
 
     my $new_ddl = $self->get_type_ddl(\%new_def_copy);
     my @statements;
+
+    # Drop the FK if the new definition doesn't have one.
+    if ($old_def->{REFERENCES} && !$new_def->{REFERENCES}) {
+        push(@statements, $self->_get_drop_fk_sql($table, $column, $old_def));
+    }
+
     push(@statements, "UPDATE $table SET $column = $set_nulls_to
                         WHERE $column IS NULL") if defined $set_nulls_to;
     push(@statements, "ALTER TABLE $table CHANGE COLUMN 
@@ -187,9 +195,30 @@ sub get_alter_column_ddl {
         # Dropping a PRIMARY KEY needs an explicit DROP PRIMARY KEY
         push(@statements, "ALTER TABLE $table DROP PRIMARY KEY");
     }
+
+    # Add the FK if the new definition has one and the old definition doesn't.
+    if ($new_def->{REFERENCES} && !$old_def->{REFERENCES}) {
+        push(@statements, $self->_get_add_fk_sql($table, $column, $new_def));
+    }
     return @statements;
 }
 
+sub _get_drop_fk_sql {
+    my ($self, $table, $column, $old_def) = @_;
+    my $fk_name = $self->_get_fk_name($table, $column, $old_def->{REFERENCES});
+    my @sql = ("ALTER TABLE $table DROP FOREIGN KEY $fk_name");
+    my $dbh = Bugzilla->dbh;
+
+    # MySQL requires, and will create, an index on any column with
+    # an FK. It will name it after the fk, which we never do.
+    # So if there's an index named after the fk, we also have to delete it. 
+    if ($dbh->bz_index_info_real($table, $fk_name)) {
+        push(@sql, $self->get_drop_index_ddl($table, $fk_name));
+    }
+
+    return @sql;
+}
+
 sub get_drop_index_ddl {
     my ($self, $table, $name) = @_;
     return ("DROP INDEX \`$name\` ON $table");

Bugzilla/Install/DB.pm

@@ -49,6 +49,39 @@ sub indicate_progress {
     }
 }
 
+# This is used before adding a foreign key to a column, to make sure
+# that the database won't fail adding the key.
+sub check_references {
+    my ($table, $column, $foreign_table, $foreign_column) = @_;
+    my $dbh = Bugzilla->dbh;
+
+    my $bad_values = $dbh->selectcol_arrayref(
+        "SELECT DISTINCT $table.$column 
+           FROM $table LEFT JOIN $foreign_table
+                ON $table.$column = $foreign_table.$foreign_column
+          WHERE $foreign_table.$foreign_column IS NULL");
+
+    if (@$bad_values) {
+        my $values = join(', ', @$bad_values);
+        print <<EOT;
+
+ERROR: There are invalid values for the $column column in the $table 
+table. (These values do not exist in the $foreign_table table, in the 
+$foreign_column column.)
+
+Before continuing with checksetup, you will need to fix these values,
+either by deleting these rows from the database, or changing the values
+of $column in $table to point to valid values in $foreign_table.$foreign_column.
+
+The bad values from the $table.$column column are:
+$values
+
+EOT
+        # I just picked a number above 2, to be considered "abnormal exit."
+        exit 3;
+    }
+}
+
 # NOTE: This is NOT the function for general table updates. See
 # update_table_definitions for that. This is only for the fielddefs table.
 sub update_fielddefs_definition {
@@ -519,6 +552,20 @@ sub update_table_definitions {
     $dbh->bz_add_column('milestones', 'id',
         {TYPE => 'MEDIUMSERIAL', NOTNULL => 1, PRIMARYKEY => 1});
 
+    # Referential Integrity begins here
+    check_references('profiles_activity', 'userid', 'profiles', 'userid');
+    $dbh->bz_alter_column('profiles_activity', 'userid',
+        {TYPE => 'INT3', NOTNULL => 1,  REFERENCES =>
+        {TABLE  => 'profiles', COLUMN => 'userid', DELETE => 'CASCADE'}});
+    check_references('profiles_activity', 'who', 'profiles', 'userid');
+    $dbh->bz_alter_column('profiles_activity', 'who',
+        {TYPE => 'INT3', NOTNULL => 1, REFERENCES =>
+        {TABLE  => 'profiles', COLUMN => 'userid'}});
+    check_references('profiles_activity', 'fieldid', 'fielddefs', 'id');
+    $dbh->bz_alter_column('profiles_activity', 'fieldid',
+        {TYPE => 'INT3', NOTNULL => 1, REFERENCES =>
+        {TABLE  => 'fielddefs', COLUMN => 'id'}});
+
     ################################################################
     # New --TABLE-- changes should go *** A B O V E *** this point #
     ################################################################