PG 触发器示例以及与之相关的常用变量

文章目录

• ​​数据​​
• ​​实例演示​​

数据

drop table if exists test cascade;
CREATE TABLE test (
  id serial,
  info text,
  create_time timestamptz
);



CREATE OR REPLACE FUNCTION func_show_trigger_info ()
RETURNS trigger AS
$$
     DECLARE
     BEGIN
          RAISE NOTICE 'NEW: %', NEW;
          RAISE NOTICE 'TG_RELID: %', TG_RELID;
          RAISE NOTICE 'TG_TABLE_SCHEMA: %', TG_TABLE_SCHEMA;
     RAISE NOTICE 'TG_TABLE_NAME: %', TG_TABLE_NAME;
          RAISE NOTICE 'TG_RELNAME: %', TG_RELNAME;
          RAISE NOTICE 'TG_OP: %', TG_OP;
          RAISE NOTICE 'TG_WHEN: %', TG_WHEN;
          RAISE NOTICE 'TG_LEVEL: %', TG_LEVEL;
                RAISE NOTICE 'TG_NARGS: %', TG_NARGS;
          RAISE NOTICE 'TG_ARGV: %', TG_ARGV;
          RAISE NOTICE ' TG_ARGV[0]: %', TG_ARGV[0];
          RETURN NEW;
     END;
$$ LANGUAGE 'plpgsql';


CREATE TRIGGER trig_test
     BEFORE INSERT ON test
     FOR EACH ROW EXECUTE PROCEDURE func_show_trigger_info('arg1','arg2');
     
INSERT INTO test (info,create_time)
   VALUES  ('info','2022-01-01 01:01:01');
 

实例演示

postgres=# INSERT INTO test (info,create_time)
postgres-#    VALUES  ('info','2022-01-01 01:01:01');
NOTICE:  NEW: (1,info,"2022-01-01 01:01:01+00")
NOTICE:  TG_RELID: 16405
NOTICE:  TG_TABLE_SCHEMA: public
NOTICE:  TG_TABLE_NAME: test
NOTICE:  TG_RELNAME: test
NOTICE:  TG_OP: INSERT
NOTICE:  TG_WHEN: BEFORE
NOTICE:  TG_LEVEL: ROW
NOTICE:  TG_NARGS: 2
NOTICE:  TG_ARGV: [0:1]={arg1,arg2}
NOTICE:  TG_ARGV[0]: arg1