如何在 postgreSQL 中删除后更新

Question

我正在尝试在删除不同表中的值后更新表。

这是我对这个问题的简化函数查询：

create function updateoutfit(_id uuid,  _title text DEFAULT NULL::text)
    returns TABLE(id uuid, title text)
    language sql
as
$$
WITH del AS (DELETE FROM outfit_garment WHERE outfit_garment.outfit_id = _id RETURNING outfit_id),
     updateOutfit AS (
       UPDATE outfit SET
         title = _title
         FROM del
         WHERE outfit.id = del.outfit_id
         RETURNING id, title
     )
SELECT id,
       title
from updateOutfit as outfit
group by id, title;
$$;

如果有delete返回的outfit_id就好了：

DELETE FROM outfit_garment WHERE outfit_garment.outfit_id = _id RETURNING outfit_id

但如果没有要删除的行则失败。我试过这样的事情：

DELETE FROM outfit_garment WHERE outfit_garment.outfit_id = '1234' RETURNING (SELECT '1234' as outfit_id );

但它仍然返回 0 行。

有没有办法解决这个问题或更好的方法？

我正在使用 postgres 13.2

Answer 1

似乎您的UPDATE 应该是无条件的。所以分开DELETE。喜欢：

CREATE FUNCTION updateoutfit(_id UUID, _title text DEFAULT NULL::text)
  RETURNS table(id UUID, title text)
  LANGUAGE sql AS
$func$
DELETE FROM outfit_garment
WHERE  outfit_garment.outfit_id = _id;

WITH upd AS (
   UPDATE outfit
   SET    title = _title
   FROM   del
   WHERE  outfit.id = _id
   RETURNING id, title
   )
SELECT DISTINCT id, title
FROM   upd;
$func$;