Mysql 增加表字段
mysql增加表字段语句如下：
alter table orders add column name varchar(20);
- 示例：
mysql> desc orders;
+-------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+----------------+
| shipaddress | int(20) | YES | MUL | NULL | |
| shipcity | varchar(20) | YES | | NULL | |
+-------------+-------------+------+-----+---------+----------------+
2 rows in set (0.02 sec)
执行sql语句：
mysql> alter table orders add column id int auto_increment primary key after shipcity;
Query OK, 0 rows affected (0.44 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> alter table orders add column name varchar(20);
Query OK, 0 rows affected (0.34 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> desc orders;
+-------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+----------------+
| shipaddress | int(20) | YES | MUL | NULL | |
| shipcity | varchar(20) | YES | | NULL | |
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(20) | YES | | NULL | |
+-------------+-------------+------+-----+---------+----------------+
4 rows in set (0.02 sec)
