数据库的基本操作之多列添加

Posted 2020-08-15

添加多列

ALTER TABLE tbl_name (ADD col_name1 column_defination1, ADD col_name2 column_defination2, ...)

注意：添加单列的时候可以指明位置关系，添加多列的时候不可以

如下

执行多列添加之前

mysql> select * from users1;
+----+----------+------+------+
| id | username | pid | age |
+----+----------+------+------+
| 3 | wuxie | 2 | 10 |
| 4 | Tom | 1 | 10 |
+----+----------+------+------+
2 rows in set (0.00 sec)

 

多列添加语句

mysql> alter table users1 add sex enum(‘1‘, ‘2‘, ‘3‘) default ‘3‘,add address varchar(30) not null;
Query OK, 0 rows affected (0.93 sec)
Records: 0 Duplicates: 0 Warnings: 0

 

多列添加以后

mysql> select * from users1;
+----+----------+------+------+------+---------+
| id | username | pid | age | sex | address |
+----+----------+------+------+------+---------+
| 3 | wuxie | 2 | 10 | 3 | |
| 4 | Tom | 1 | 10 | 3 | |
+----+----------+------+------+------+---------+
2 rows in set (0.00 sec)