从MySQL表中删除数据后如何自动加1？
为此，您可以使用TRUNCATETABLE命令。让我们首先创建一个表-
mysql> create table DemoTable1796
(
StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
StudentName varchar(20)
);使用插入命令在表中插入一些记录-
mysql> insert into DemoTable1796(StudentName) values('Chris Brown');
mysql> insert into DemoTable1796(StudentName) values('David Miller');
mysql> insert into DemoTable1796(StudentName) values('John Doe');使用select语句显示表中的所有记录
mysql> select * from DemoTable1796;
这将产生以下输出
+-----------+--------------+ | StudentId | StudentName | +-----------+--------------+ | 1 | Chris Brown | | 2 | David Miller | | 3 | John Doe | +-----------+--------------+ 3 rows in set (0.00 sec)
这是从表中删除记录的查询-
mysql> delete from DemoTable1796;
现在将记录插入表中
mysql> insert into DemoTable1796(StudentName) values('John Doe');
mysql> select * from DemoTable1796;
+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
| 4 | John Doe |
+-----------+-------------+
1 row in set (0.00 sec)现在您可以使用TRUNCATETABLE命令
mysql> truncate table DemoTable1796;
现在，让我们将一些记录插入表中
mysql> insert into DemoTable1796(StudentName) values('John Doe');
mysql> select * from DemoTable1796;
+-----------+-------------+
| StudentId | StudentName |
+-----------+-------------+
| 1 | John Doe |
+-----------+-------------+
1 row in set (0.00 sec)