Question

每当用户从表中删除数据时，我都会触发SQL触发器。我要在删除当前数据之前更新另一个表。我无法获取当前已删除的行数据。如何在SQL触发器中获取当前已删除数据的内容。

CREATE TRIGGER `before_insert_money` BEFORE DELETE ON `payment`
  FOR EACH ROW BEGIN
    DECLARE TEMP INT;
    SELECT   OLD.user_id  into TEMP      
    FROM OLD;

    UPDATE user set monthly_limit=TEMP where id=1;

 END

Answer 1

您只需要引用OLD.userid，而不是存储到另一个变量TEMP中。另外，在OLD子句中没有可用的FROM表。您只需要使用OLD.<column name>来为要删除的行使用特定列的值。

DELIMITER $$
CREATE TRIGGER `before_insert_money` BEFORE DELETE ON `payment`
  FOR EACH ROW BEGIN

    UPDATE user set monthly_limit = OLD.user_id where id=1;

  END $$
DELIMITER ;

Answer 2

这将按您希望删除内容的方式工作：

SELECT * FROM NS_WORDS;

mani
nikhil
sugandh
mining
_lkdnsad
_lkdndsadnjas
_lk
_ja
_ls
_lsa

create table deleted_vals(a varchar(20));

CREATE OR REPLACE TRIGGER trigger_deleted_vals
BEFORE DELETE
   ON NS_WORDS
   FOR EACH ROW
DECLARE
BEGIN
INSERT INTO deleted_vals VALUES(:old.a);
END;
/

delete from NS_WORDS where rownum=1;

SELECT * FROM deleted_vals;

mani

for your table it would be like:

    CREATE TRIGGER before_insert_money
    BEFORE DELETE ON payment
    FOR EACH ROW 
    BEGIN

    UPDATE user set monthly_limit=:old.user_id where id=1;

 END;
 /

我如何在Sql触发器中获取当前已删除的行的值并使用已删除的行数据更新另一个表

2 个答案: