openGauss每日一练第18天 | 学习openGauss触发器

课后作业
1.创建源表和触发表，在源表上创建insert触发器，创建操作触发表的触发器函数

create table eason1(id1 int,id2 int,id3 int);
create table eason2(id1 int,id2 int,id3 int);
CREATE OR REPLACE FUNCTION tri_insert_func() RETURNS TRIGGER AS
$$
DECLARE
BEGIN
INSERT INTO eason1 VALUES(NEW.id1, NEW.id2, NEW.id3);
RETURN NEW;
END
$$ LANGUAGE PLPGSQL;
CREATE TRIGGER insert_trigger
BEFORE INSERT ON eason2
FOR EACH ROW
EXECUTE PROCEDURE tri_insert_func();

2.在源表上执行insert操作，查看触发操作是否生效；禁用触发器后，再次查看触发操作是否生效

INSERT INTO eason2 VALUES(100,200,300);
select * from eason1;
select * from eason2;

alter table eason2 disable trigger insert_trigger;
INSERT INTO eason2 VALUES(400,500,600);
select * from eason1;
select * from eason2;

3.使用系统表PG_TRIGGER和\dS+查看触发器

select * from pg_trigger;
\dS+ eason2

4.重命名触发器

alter trigger insert_trigger on eason2 rename to insert_trigger_renamed;

5.删除触发器

drop trigger insert_trigger_renamed on eason2;