MySQL ALTER int列は、外国キーとのBigIntへ

Question

INTからBIGINTへのデータベース内の一部のプライマリキー列のデータ型を変更します。以下の定義は、問題を説明するための玩具例です：

CREATE TABLE IF NOT EXISTS `owner` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `thing_id` int(11) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `thing_id` (`thing_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ;

DROP TABLE IF EXISTS `thing`;
CREATE TABLE IF NOT EXISTS `thing` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ;

ALTER TABLE `owner`
  ADD CONSTRAINT `owner_ibfk_1` FOREIGN KEY (`thing_id`) REFERENCES `thing` (`id`);

.

次のコマンドのいずれかを実行しようとすると、

ALTER TABLE `thing` CHANGE `id` `id` BIGINT NOT NULL AUTO_INCREMENT;
ALTER TABLE `owner` CHANGE `thing_id` `thing_id` BIGINT NOT NULL;

.

私はエラーに遭遇しています

#1025 - Error on rename of './debug/#[temp-name]' to './debug/[tablename]' (errno: 150)

.

INODBステータス出力を表示：

LATEST FOREIGN KEY ERROR
------------------------
120126 13:34:03 Error in foreign key constraint of table debug/owner:
there is no index in the table which would contain
the columns as the first columns, or the data types in the
table do not match the ones in the referenced table
or one of the ON ... SET NULL columns is declared NOT NULL. Constraint:
,
 CONSTRAINT "owner_ibfk_1" FOREIGN KEY ("thing_id") REFERENCES "thing" ("id")

.

外部キー定義が両側の列の種類を変更することをブロックすると推測しています。この問題を解決するための素朴なアプローチは、外部キー定義を削除し、列を変更し、外部キーを再定義することです。より良い解決策はありますか？

Answer 1

Even with SET foreign_key_checks = 0, you can't alter the type of the constraint column. From MySQL doc : http://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html

However, even if foreign_key_checks = 0, InnoDB does not permit the creation of a foreign key constraint where a column references a nonmatching column type.

So, I agree with the comment of Devart. Just drop it and create it again.

Answer 2

I could suggest you to rename such fields in GUI tool - dbForge Studio for MySQL (free trial edition):

Just select the field you want to rename in the Database Explorer, click on Refactoring->Rename command, enter new name in openned window, and press OK, it will rename the field and recreate all foreign keys automatically.

Answer 3

I had a similar problem the solution is the change clause:

ALTER TABLE table_name CHANGE id id BIGINT(20) NOT NULL AUTO_INCREMENT;

That worked for me.