Postgresql 运算符不存在整数：refcursor，42883 | Postgres

我必须从3个表中删除记录。从第三个tableParent表中删除的条件是，只有在不存在子记录的情况下才应删除该表。我正在使用游标并尝试使用游标从表中删除。我试图执行函数，但我面临着标题中提到的错误。下面是我的代码：-

CREATE OR REPLACE FUNCTION housekeeping(
   OUT p_message_out CHARACTER VARYING,
   OUT p_sqlstate_out CHARACTER VARYING
   )
   RETURNS RECORD AS 
$BODY$

DECLARE 
v_msg CHARACTER VARYING(160);
v_sqlstate CHARACTER VARYING(6);
v_id INTEGER;
c_del CURSOR FOR SELECT employee_id FROM notification WHERE  sys_time<=CURRENT_TIMESTAMP - INTERVAL '30 Days';
v_del REFCURSOR;

BEGIN

OPEN c_del;
LOOP
FETCH c_del INTO v_del;
EXIT WHEN NOT FOUND;
delete from client where payment_id in(select payment_id from notification where sys_time<=CURRENT_TIMESTAMP - INTERVAL '30 Days');

delete from notification where sys_time<=CURRENT_TIMESTAMP - INTERVAL '30 Days';

select count(*) into v_id from notification where employee_id=v_del;
IF v_id=0 THEN
delete from employee where employee_id=v_del;
END IF;
END LOOP;

v_msg = 'Data deleted successfully.';
v_sqlstate = 1; 

p_message_out = v_msg;
p_sqlstate_out = v_sqlstate;

--Exception handling
EXCEPTION WHEN OTHERS THEN
p_message_out=SQLERRM;
p_sqlstate_out=SQLSTATE;

END;
$BODY$
  LANGUAGE plpgsql VOLATILE SECURITY DEFINER

---

这样做不需要循环甚至变量

您可以使用关联子查询有条件地删除末尾的员工

CREATE OR REPLACE FUNCTION housekeeping
   (
     OUT p_message_out CHARACTER VARYING,
     OUT p_sqlstate_out CHARACTER VARYING
   )
   RETURNS RECORD AS 
$BODY$
BEGIN
  delete from client 
  where payment_id in (select payment_id 
                       from notification 
                       where sys_time <= CURRENT_TIMESTAMP - INTERVAL '30 Days');

  delete from notification 
  where sys_time <= CURRENT_TIMESTAMP - INTERVAL '30 Days';

  -- delete all employees for which no notification exists
  delete from employee emp
  where not exists (select *
                    from notification n
                    where n.employee_id = emp.employee_id);

  p_message_out  := 'Data deleted successfully.';
  p_sqlstate_out := 1; 

EXCEPTION WHEN OTHERS THEN
  --Exception handling
  p_message_out := SQLERRM;
  p_sqlstate_out := SQLSTATE;
END;
$BODY$
LANGUAGE plpgsql;

---

但v_id用于计算通知表中是否存在行。如果行不存在，则需要继续删除。此外，它可能包含多个员工id。因此，我们使用游标。如果我错了，请纠正我。你太棒了！！！！！！！！！！！我想用不同的例子来学习游标。你能给我推荐一些链接吗？@Nik：当你考虑使用关系数据库的游标或循环时，请重新考虑。这不是做事的自然方法。基于集合的方法几乎总是更好的选择。与其专注于学习游标，不如学习如何应用基于集合的解决方案。