protected function loadTablePrimaryKey($tableName)
    {
        $primaryKey = $this->db->getSlavePdo()->cubrid_schema(\PDO::CUBRID_SCH_PRIMARY_KEY, $tableName);
        if (empty($primaryKey)) {
            return null;
        }

        ArrayHelper::multisort($primaryKey, 'KEY_SEQ', SORT_ASC, SORT_NUMERIC);
        return new Constraint([
            'name' => $primaryKey[0]['KEY_NAME'],
            'columnNames' => ArrayHelper::getColumn($primaryKey, 'ATTR_NAME'),
        ]);
    }
protected function loadTablePrimaryKey($tableName)
    {
        $primaryKey = $this->db->getSlavePdo()->cubrid_schema(\PDO::CUBRID_SCH_PRIMARY_KEY, $tableName);
        if (empty($primaryKey)) {
            return null;
        }

        ArrayHelper::multisort($primaryKey, 'KEY_SEQ', SORT_ASC, SORT_NUMERIC);
        return new Constraint([
            'name' => $primaryKey[0]['KEY_NAME'],
            'columnNames' => ArrayHelper::getColumn($primaryKey, 'ATTR_NAME'),
        ]);
    }
{@inheritdoc}