如何获取触发器的插入值 [英] How to get inserted value for trigger

问题描述

我正在尝试在mysql中创建一个触发器，该触发器将在插入表时插入到另一个表中.

I am trying to create a trigger in mysql that will insert in to another table when an insert on a table occurs.

CREATE TRIGGER addCardForNewUser AFTER INSERT ON swiped.Users
FOR EACH ROW
  BEGIN
      INSERT INTO swiped.Card (userid) VALUES (get value from original insert here);
  END

在insert语句的values部分中，我如何从原始insert中获取一个值以在此处使用?

In the values part of the insert statement how would i get a value from the original insert to use here?

谢谢

推荐答案

您可以将这些值与new.columnname一起使用.如果该列的名称也为userid，则可以使用:

You can use those values with new.columnname. If the name of the column is userid too, then you can use:

CREATE TRIGGER addCardForNewUser AFTER INSERT ON swiped.Users
FOR EACH ROW
  BEGIN
      INSERT INTO swiped.Card (userid) VALUES (new.userid);
  END

从官方文档中:

在触发器主体内，OLD和NEW关键字使您可以访问 受触发器影响的行中的列.旧的和新的是MySQL 触发器的扩展；它们不区分大小写.

Within the trigger body, the OLD and NEW keywords enable you to access columns in the rows affected by a trigger. OLD and NEW are MySQL extensions to triggers; they are not case sensitive.

在INSERT触发器中，只能使用NEW.col_name

In an INSERT trigger, only NEW.col_name can be used

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