程序媛计划——mysql修改表结构

#查看表的结构

mysql> desc score;

+------------+--------------+------+-----+---------+----------------+

| Field      | Type         | Null | Key | Default | Extra          |

+------------+--------------+------+-----+---------+----------------+

| id         | int(4)       | NO   | PRI | NULL    | auto_increment |

| name       | char(20)     | NO   |     | NULL    |                |

| score      | double(16,2) | YES  |     | NULL    |                |

| evaluation | char(20)     | YES  |     | normal  |                |

+------------+--------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

#alter对字段操作

#添加字段

mysql> alter table exam_score add other int(4) default 10;

Query OK, 0 rows affected (0.05 sec)

Records: 0  Duplicates: 0  Warnings: 0

#修改字段变为另一个字段

mysql> alter table exam_score change other evaluation char(20) default 'normal';

Query OK, 4 rows affected (0.02 sec)

Records: 4  Duplicates: 0  Warnings: 0

#删除字段(即删除字段中的所有数据)

mysql> alter table exam_score drop column other;

Query OK, 0 rows affected (0.05 sec)

Records: 0  Duplicates: 0  Warnings: 0

#修改表名

mysql> rename table exam_score to score;

Query OK, 0 rows affected (0.01 sec)

巴特西

程序媛计划——mysql修改表结构

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