postgresql创建函数触发器如何实现？下面是有错的，看看哪位大神能否帮忙纠正
第一步 CREATE OR REPLACE FUNCTION insert_table2 () RETURNS trigger VOLATILE AS $pgsql$ BEGIN insert into DW.base_emp_all_data_d select * from ODS.ods_emp_detail_d WHERE to_char(etl_dt,'yyyymmdd') = 'v_in_date'; end; $pgsql$ LANGUAGE plpgsql; 第二步 create trigger "example_trigger" after insert on DW.base_emp_all_data_d FOR EACH ROW EXECUTE PROCEDURE insert_table2 (); 第三步insert into ods.ods_emp_detail_d(EMPNO,ENAME,JOB,MGR,HIREDATE,SAL,DEPTNO) values(7935,'MILLER','CLERK',7782,'1982-1-23',1300,10); select * from DW.base_emp_all_data_d; select * from ods.ods_emp_detail_d;