CREATE TRIGGER TR_chk_statoPartita after INSERT ON Partita FOR EACH ROW BEGIN DELETE FROM Partita WHERE NEW.stato > 2; END; // when I try to insert value to Partita I get the error message: ERROR 1442 (HY000): Can't update table 'partita' in stored function/trigger because ...
示例代码 DELIMITER//CREATETRIGGERprevent_delete_employees BEFOREDELETEONemployeesFOR EACH ROWBEGINSIGNAL SQLSTATE'45000'SETMESSAGE_TEXT='数据删除操作被阻止!';END;//DELIMITER; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 代码解析 DELIMITER: 用于更改语句结束符,使得创建触发器时可以使用;作为SQL语句的...
创建触发器 要创建一个触发器,我们需要使用MySQL的CREATE TRIGGER语句。 CREATETRIGGERtrigger_name {BEFORE|AFTER} {INSERT|UPDATE|DELETE}ONtable_nameFOR EACH ROWBEGIN-- 触发器执行的操作END; 1. 2. 3. 4. 5. 6. trigger_name:触发器的名称,必须是唯一的。 BEFORE或AFTER:指定触发器的执行时间,BEFORE表示...
MySQL触发器在某些条件下阻止INSERTMySQL触发器在某些条件下阻止INSERT 我想制作一个触发器,如果未来的生日(其中一列),将阻止插入。我有这个: CREATE TRIGGER foo BEFORE INSERT ON tableFOR EACH ROWBEGIN IF NEW.birthdate > CURRENT_DATE() THEN //How do I prevent the insert right here??? END IF;END;...
DELIMITER $$ CREATE TRIGGER `before_employee_update` BEFORE UPDATE ON `employees` FOR EACH ROW BEGIN IF NEW.salary < 0 THEN LEAVE before_employee_update; END IF; END$$ DELIMITER ; 解决问题的步骤 识别问题:确定触发器抛出的具体异常信息。
CREATE TRIGGER `prevent_negative_number` BEFORE INSERT ON `test`FOR EACH ROW BEGIN IF NEW.number SIGNAL SQLSTATE ‘45000’ SET MESSAGE_TEXT = ‘The number must not be negative’;END IF;END;在上面的代码中，我们创建了一个名为”prevent_negative_number&...
This in particular has a major impact on triggers, since a missing table referenced by an update/delete trigger would prevent an insert trigger to run. Another problem is that stored routines might define SQL exception handlers to deal with missing tables, but the server implementation would ...
消息:%strigger中不允许更新%s行 错误:1363SQLSTATE: () HY000 ER_TRG_NO_SUCH_ROW_IN_TRG 消息:%s触发器中没有%s行 错误:1364SQLSTATE: () HY000 ER_NO_DEFAULT_FOR_FIELD 消息:字段’%s’没有默认值 错误:1365SQLSTATE: () 22012 ER_DIVISION_BY_ZERO ...
prevent this scenario.Temporary tables.CREATE TEMPORARY TABLE(https://dev.mysql.com/doc/refman/5.7/en/create-table.html)andDROP TEMPORARY TABLE(https://dev.mysql.com/doc/refman/5.7/en/drop-table.html)statements are not supported inside transactions, procedures, functions, and triggers when using...
DROP TRIGGER IF EXISTS Insert_attitudeData_event; CREATE TRIGGER Insert_attitudeData_event AFTER INSERT ON tbAttitudeData FOR EACH ROW -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. BEGIN DECLARE Id VARCHAR (50); DECLARE Ax FLOAT; DECLARE Ay...