mysql insert into, insert ignore into, insert into on duplicate key update

目录

• insert into
• insert ignore into
• insert into on duplicate update
  • 不存在记录时
• insert ignore into on duplicate update
  • 不存在记录时

几个sql的执行情况汇总如下表：

指令	已存在	不存在
insert	报错	插入
insert ignore	忽略	插入
insert into on duplicate key update	更新	插入
insert ignore into on duplicate key update	更新	插入

数据表要求有主键或唯一键。

另外，以上操作，都会使自增字段自增。

下面做下具体的测试。

建表

CREATE TABLE `test5` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(45) NOT NULL,
  `age` tinyint(4) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`),
  UNIQUE KEY `name_UNIQUE` (`name`)
) ENGINE=InnoDB;

id是主键，自增，name是唯一键。

insert into

> insert into test5 (name, age) values('John', 1);
Query OK, 1 row affected (0.00 sec)

查询

mysql> select * from test5;
+----+------+-----+
| id | name | age |
+----+------+-----+
|  1 | John |   1 |
+----+------+-----+
1 row in set (0.00 sec)

已插入新记录。

再次插入

mysql> insert into test5 (name, age) values('John', 1);
ERROR 1062 (23000): Duplicate entry 'John' for key 'name_UNIQUE'

报错，唯一键冲突。

insert ignore into

mysql> insert ignore into test5 (name, age) values('John', 1);
Query OK, 0 rows affected, 1 warning (0.00 sec)

查询

mysql> select * from test5;
+----+------+-----+
| id | name | age |
+----+------+-----+
|  1 | John |   1 |
+----+------+-----+
1 row in set (0.00 sec)

ignore 会忽略错误。

insert into on duplicate update

mysql> insert into test5 (name, age) values('John', 2) on duplicate key update age=2;
Query OK, 2 rows affected (0.00 sec)

查询

mysql> select * from test5;
+----+------+-----+
| id | name | age |
+----+------+-----+
|  1 | John |   2 |
+----+------+-----+
1 row in set (0.00 sec)

age更新为2。

不存在记录时

mysql> insert into test5 (name, age) values('Alex', 2) on duplicate key update age=2;
Query OK, 1 row affected (0.00 sec)

查询

mysql> select * from test5;
+----+------+-----+
| id | name | age |
+----+------+-----+
|  1 | John |   2 |
|  7 | Alex |   2 |
+----+------+-----+
2 rows in set (0.00 sec)

会插入新记录。

insert ignore into on duplicate update

mysql> insert ignore into test5 (name, age) values('John', 3) on duplicate key update age=3;
Query OK, 2 rows affected (0.01 sec)

查询

mysql> select * from test5;
+----+------+-----+
| id | name | age |
+----+------+-----+
|  1 | John |   3 |
|  7 | Alex |   2 |
+----+------+-----+
2 row in set (0.00 sec)

John的age更新为3。

不存在记录时

mysql> insert ignore into test5 (name, age) values('Bob', 3) on duplicate key update age=3;
Query OK, 1 row affected (0.00 sec)

mysql> select * from test5;
+----+------+-----+
| id | name | age |
+----+------+-----+
|  1 | John |   3 |
|  7 | Alex |   2 |
|  8 | Bob  |   3 |
+----+------+-----+
3 rows in set (0.00 sec)

会插入新记录。