protected function preparePrimaryKeyCreateStatement4Update(DataSourceHandler $handler, DatasetMetaData $dataset)
 {
     $sql = parent::preparePrimaryKeyCreateStatement4Update($handler, $dataset);
     if (!isset($sql)) {
         return NULL;
     }
     $primaryKeyConstraintColumns = $dataset->getKeyColumnNames();
     $firstColumnName = reset($primaryKeyConstraintColumns);
     return $this->fixForeignKeyProblem($handler, $dataset, $firstColumnName, TRUE, $sql);
 }