MySQLで挿入できるレコードの文字数制限を変更する方法

ALTER文使おう

ALTER文を使ってテーブル構造の情報を変更してあげれば良い。

mysql> DESC {table_name};
+------------+---------------------+------+-----+---------+----------------+
| Field      | Type                | Null | Key | Default | Extra          |
+------------+---------------------+------+-----+---------+----------------+
| id         | bigint(20) unsigned | NO   | PRI | NULL    | auto_increment |
| title      | varchar(255)        | NO   |     | NULL    |                |
| contents   | varchar(255)        | NO   |     | NULL    |                |
| created_at | timestamp           | YES  |     | NULL    |                |
| updated_at | timestamp           | YES  |     | NULL    |                |
+------------+---------------------+------+-----+---------+----------------+

contentsカラムをvarchar(2000)にしたい。

mysql> ALTER TABLE {table_name} MODIFY COLUMN contents varchar(1000);

mysql> desc {table_name};
+------------+---------------------+------+-----+---------+----------------+
| Field      | Type                | Null | Key | Default | Extra          |
+------------+---------------------+------+-----+---------+----------------+
| id         | bigint(20) unsigned | NO   | PRI | NULL    | auto_increment |
| title      | varchar(255)        | NO   |     | NULL    |                |
| contents   | varchar(1000)       | YES  |     | NULL    |                |
| created_at | timestamp           | YES  |     | NULL    |                |
| updated_at | timestamp           | YES  |     | NULL    |                |
+------------+---------------------+------+-----+---------+----------------+

oh yeah~♪