mysql> create table t_Myxiao7(id int not null auto_increment primary key ,name v
archar(10), genda varchar(10),age int);
Query OK, 0 rows affected (0.08 sec)

mysql> insert into t_Myxiao7 values
    -> (null,'张三','男',20),
    -> (null,'王五','男',22),
    -> (null,'李四','男',25),
    -> (null,'陈大','男',19);
Query OK, 4 rows affected (0.05 sec)
Records: 4  Duplicates: 0  Warnings: 0

mysql>
mysql> select * from t_Myxiao7;
+----+------+-------+------+
| id | name | genda | age  |
+----+------+-------+------+
|  1 | 张三 | 男    |   20 |
|  2 | 王五 | 男    |   22 |
|  3 | 李四 | 男    |   25 |
|  4 | 陈大 | 男    |   19 |
+----+------+-------+------+
4 rows in set (0.01 sec)

mysql> delete from t_Myxiao7 where id=3 or id =4;
Query OK, 2 rows affected (0.08 sec)

mysql> select * from t_Myxiao7;
+----+------+-------+------+
| id | name | genda | age  |
+----+------+-------+------+
|  1 | 张三 | 男    |   20 |
|  2 | 王五 | 男    |   22 |
+----+------+-------+------+
2 rows in set (0.00 sec)

mysql> alter table t_Myxiao7 AUTO_INCREMENT 3;
Query OK, 2 rows affected (0.19 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> insert into t_Myxiao7 values
    -> (null,'春哥','男','27');
Query OK, 1 row affected (0.06 sec)

mysql> select * from t_Myxiao7;
+----+------+-------+------+
| id | name | genda | age  |
+----+------+-------+------+
|  1 | 张三 | 男    |   20 |
|  2 | 王五 | 男    |   22 |
|  3 | 春哥 | 男    |   27 |
+----+------+-------+------+
3 rows in set (0.00 sec)

mysql>