mysql触发器TRIGGER实例
查询:SELECT * FROM information_schema.triggers;删除:drop trigger trigger_name;
实例：
DELIMITER $
CREATE TRIGGER FRCHANCOUNTRY
BEFORE
INSERT ON orders
FOR EACH ROW
BEGIN
DECLARE d VARCHAR(20);
SET d = LEFT(NEW.buyer_zip,3);
IF (new.buyer_country_code = 'FR' AND d=974)
THEN
SET NEW.buyer_country_code = 'RE';
SET NEW.buyer_country = 'Reunion';
END IF;
end;
$
DELIMITER;
创建名为FRCHANCOUNTRY,在insert插入数据库表orders前修改信息
NEW代表insert的数据
sql语句:
insert into orders(buyer_zip,buyer_country_code,buyer_country,buyer_zip) values('974125','FR','France');
最终插入结果的执行语句为:
insert into orders(buyer_zip,buyer_country_code,buyer_country,buyer_zip) values('974125','RE','Reunion');
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