mysql触发器存储的触发器已被调用存储触发器的语句使用 [英] mysql trigger stored trigger is already used by statement which invoked stored trigger

问题描述

我想设置一个触发器，以便如果更新时预测字段为= 3，则触发器将值更改为4并将其保存在数据库中.触发器在下面.

I want to set up a trigger so that if on an update the prediction field is = 3 then the trigger changes the value to 4 and saves it in the database. The trigger is below.

由于某种原因，我总是收到错误消息:

For some reason I keep getting an error saying:

#1442 - Can't update table 'tzanalytic\_forecast\_cached' in stored 
function/trigger because it is already used by statement which invoked 
this stored function/trigger.

此设置是否正确?

delimiter $$ 
CREATE TRIGGER no_BoW BEFORE UPDATE ON t FOR EACH ROW 
BEGIN set @prediction = new.prediction; 
UPDATE t SET t.prediction = (SELECT IF(@prediction = '3', '4', @prediction)) WHERE t.event_id = new.event_id AND t.price_tier = new.price_tier; END;
$$ delimiter ;

推荐答案

MySQL触发器无法操纵分配给它们的表.所有其他主要的DBMS都支持此功能，因此希望MySQL会尽快添加此支持.

MySQL triggers can't manipulate the table they are assigned to. All other major DBMS support this feature so hopefully MySQL will add this support soon.

http://forums.mysql.com/read. php?99,122354,240978#msg-240978

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