public function delete() { $sql = sprintf("DELETE FROM {$this->context->consumer_instance->dbTableNamePrefix}" . BasicLTI_Tool_Provider::USER_TABLE_NAME . " WHERE consumer_instance_guid = %s AND context_id = %s AND user_id = %s", BasicLTI_Tool_Provider::quoted($this->context->consumer_instance->guid), BasicLTI_Tool_Provider::quoted($this->context->id), BasicLTI_Tool_Provider::quoted($this->id)); $ok = mysql_query($sql); return $ok; }