openGauss每日一练第18天 触发器

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 test_trigger_src_tbl(id1 INT, id2 INT, id3 INT) ;
CREATE TABLE test_trigger_des_tbl(id1 INT, id2 INT, id3 INT);

CREATE OR REPLACE FUNCTION tri_insert_func() RETURNS TRIGGER AS
$$
DECLARE
BEGIN
INSERT INTO test_trigger_des_tbl VALUES(NEW.id1, NEW.id2, NEW.id3);
RETURN NEW;
END
$$ LANGUAGE PLPGSQL;

CREATE TRIGGER insert_trigger
BEFORE INSERT ON test_trigger_src_tbl
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 test_trigger_src_tbl VALUES(100,200,300);
SELECT * FROM test_trigger_src_tbl;
SELECT * FROM test_trigger_des_tbl;
ALTER TABLE test_trigger_src_tbl DISABLE TRIGGER insert_trigger;
INSERT INTO test_trigger_src_tbl VALUES(100,200,300);
SELECT * FROM test_trigger_src_tbl;
SELECT * FROM test_trigger_des_tbl;
3.使用系统表PG_TRIGGER和\dS+查看触发器
select * from PG_TRIGGER;
\dS+ test_trigger_src_tbl
4.重命名触发器
ALTER TRIGGER delete_trigger ON test_trigger_src_tbl RENAME TO delete_trigger_renamed;
5.删除触发器
DROP TRIGGER update_trigger ON test_trigger_src_tbl;
DROP TRIGGER delete_trigger_renamed ON test_trigger_src_tbl;