MODIFY 修改

1. MODIFY 改變資料表 tbl 欄位 c 的格式由原固定 1 個字元改為 10 個字元。

   MariaDB root@(none):dyw> alter table tbl modify c char(10);
   You're about to run a destructive command.
   Do you want to proceed? (y/n): y
   Your call!
   Query OK, 4 rows affected
   Time: 0.124s
   

2. 再查看資料表 tbl 的欄位格式。

   MariaDB root@(none):dyw> desc tbl;
   +-----------------+--------------+------+-----+---------+----------------+
   | Field           | Type         | Null | Key | Default | Extra          |
   +-----------------+--------------+------+-----+---------+----------------+
   | ti              | tinyint(4)   | YES  |     | <null>  |                |
   | id              | int(11)      | NO   | PRI | <null>  | auto_increment |
   | c               | char(10)     | YES  |     | <null>  |                |
   | title           | varchar(100) | NO   |     | <null>  |                |
   | author          | varchar(40)  | NO   |     | <null>  |                |
   | submission_date | date         | YES  |     | <null>  |                |
   +-----------------+--------------+------+-----+---------+----------------+
   
   6 rows in set
   Time: 0.026s