/**
* 指定テーブルの外部キーを取得する
*
* @param string $table_name
* @return array
*/
protected function getForeignKeys($table_name, $columns = null)
{
$fks = [];
$sql = 'SELECT
CONSTRAINT_NAME,
TABLE_NAME,
COLUMN_NAME,
REFERENCED_TABLE_NAME,
REFERENCED_COLUMN_NAME
FROM information_schema.KEY_COLUMN_USAGE
WHERE REFERENCED_TABLE_SCHEMA = DATABASE()
AND REFERENCED_TABLE_NAME IS NOT NULL
AND TABLE_NAME = ?
ORDER BY POSITION_IN_UNIQUE_CONSTRAINT';
$results = $this->db->build($sql, $table_name)->fetchAll();
foreach ($results as $result) {
if (!is_null($columns) && !in_array($result->COLUMN_NAME, $columns)) {
continue;
}
$fk = new ForeignKey();
$fk->setColumnName($result->COLUMN_NAME)->setRefTableName($result->REFERENCED_TABLE_NAME)->setRefColumnName($result->REFERENCED_COLUMN_NAME)->setConstraint($result->CONSTRAINT_NAME);
$fks[] = $fk;
}
return $fks;
}
