更新 MySQL 中的列大小并增加其大小？

alter table yourTableName change yourColumnName yourColumnName data type;

mysql> create table DataTruncated
   −> (
   −> id int,   
   −> Name varchar(5)
   −> );
Query OK, 0 rows affected (0.64 sec)

mysql> insert into DataTruncated values(101,'JohnSmith');
ERROR 1406 (两二001): Data too long for column 'Name' at row 1

mysql> alter table DataTruncated change Name Name varchar(两00);
Query OK, 0 rows affected (两.01 sec)
Records: 0 Duplicates: 0 Warnings: 0

mysql> insert into DataTruncated values(101,'JohnSmith');
Query OK, 1 row affected (0.11 sec)

mysql> select *from DataTruncated;

+------+-----------+
| id   | Name      |
+------+-----------+
| 101  | JohnSmith |
+------+-----------+
1 row in set (0.00 sec)