MySQL 在触发器里中断记录的插入或更新？【MySQL】

数据库|mysql教程

触发器,mysql,记录

数据库-mysql教程

下面是一种实现的方法。思路就是想办法在触发器中利用一个出错的语句来中断代码的执行。

mysql> create table t_control(id int primary key);

Query OK, 0 rows affected (0.11 sec)

mysql> insert into t_control values (1);

Query OK, 1 row affected (0.05 sec)

mysql> create table t_bluerosehero(id int primary key,col int);

Query OK, 0 rows affected (0.11 sec)

mysql> delimiter //

mysql> create trigger tr_t_bluerosehero_bi before insert on t_bluerosehero

-> for each row

-> begin

-> if new.col>30 then

-> insert into t_control values (1);

-> end if;

-> end;

-> //

Query OK, 0 rows affected (0.08 sec)

mysql> delimiter ;

mysql>

mysql> insert into t_bluerosehero values (1,20);

Query OK, 1 row affected (0.25 sec)

mysql> insert into t_bluerosehero values (2,40);

ERROR 1062 (23000): Duplicate entry ‘1’ for key ‘PRIMARY’

mysql>

mysql> select * from t_bluerosehero;

+—-+——+

| id | col |

+—-+——+

| 1 | 20 |

+—-+——+

1 row in set (0.00 sec)

mysql>

或者

mysql> delimiter //

mysql> create trigger tr_t_bluerosehero_bi before insert on t_bluerosehero

-> for each row

-> begin

-> declare i int;

-> if new.col>30 then

-> insert into xxxx values (1);

-> end if;

-> end;

-> //

Query OK, 0 rows affected (0.06 sec)

mysql> delimiter ;

mysql> delete from t_bluerosehero;

Query OK, 3 rows affected (0.05 sec)

mysql> insert into t_bluerosehero values (1,20);

Query OK, 1 row affected (0.06 sec)

mysql> insert into t_bluerosehero values (2,40);

ERROR 1146 (42S02): Table ‘csdn.xxxx’ doesn’t exist

mysql>

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