关于Mysql中 select last_insert_id() 取值问题

mysql中可以设置主键自增:

mysql> create table t1(id int primary key auto_increment,name varchar(20));
Query OK, 0 rows affected (0.00 sec)

mysql> desc t1;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | varchar(20) | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)


mysql> create table t2(id int primary key auto_increment,name varchar(20));
Query OK, 0 rows affected (0.00 sec)

mysql> desc t2;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | varchar(20) | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)

新建了两张测试版 t1 t2 后我们开始写数据，然后用select last_insert

mysql> insert into t1(name) values('xugq');
Query OK, 1 row affected (0.00 sec)

mysql> select last_insert_id();
+------------------+
| last_insert_id() |
+------------------+
|                1 |
+------------------+
1 row in set (0.00 sec)

mysql> insert into t2(name) values('xugq');
Query OK, 1 row affected (0.00 sec)

mysql> select last_insert_id();
+------------------+
| last_insert_id() |
+------------------+
|                1 |
+------------------+
1 row in set (0.00 sec)