当我在 AUTO_INCRMENT MySQL 列中插入值“NULL”时会发生什么？

当我们向 AUTO_INCRMENT 列插入 NULL 值时，MySQL 将返回序列号。

示例

mysql> Create table employee(id INT NOT NULL PRIMARY KEY AUTO_INCREMENT, Name Varchar(10));
Query OK, 0 rows affected (0.16 sec)

mysql> Insert into employee(id, Name) values(NULL, 'Gaurav');
Query OK, 1 row affected (0.07 sec)

mysql> Select * from employee;
+----+---------+
| id | Name    |
+----+---------+
| 1  | Gaurav  |
+----+---------+
1 row in set (0.00 sec)