如何在MySQL中已创建的表中插入AUTO_INCREMENT

使用ALTER命令。让我们先创建一个表-

mysql> create table DemoTable -> ( -> StudentName varchar(100) -> ); Query OK, 0 rows affected (0.46 sec)

以下是插入AUTO_INCREMENT−的查询

alter table DemoTable ADD COLUMN StudentId int NOT NULL; alter table DemoTable ADD PRIMARY KEY(StudentId); alter table DemoTable CHANGE StudentId StudentId int NOT NULL AUTO_INCREMENT;

使用INSERT命令−在表中插入一些记录

mysql> insert into DemoTable(StudentName) values(Chris); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(StudentName) values(David); Query OK, 1 row affected (0.15 sec)

使用SELECT语句显示表中的所有记录

mysql> select *from DemoTable;

输出结果

+-------------+-----------+ | StudentName | StudentId | +-------------+-----------+ | Chris | 1 | | David | 2 | +-------------+-----------+ 2 rows in set (0.00 sec)