如何執行以下SQL總和？

Question

假設我們有下表

match_id, user_id, score

1000, 1, 359
1000, 52, 290
1001, 1, 429
1001, 59, 374

基本上在match_id 1000中，user_id 1贏得359-290，在match_id 1001中，user_id 1贏得429-374

計算用戶1的總積分很容易

select user_id,sum(score) as pointsfor group by user_id

我如何確定得分得分？ 基本上，以下SQL中的X應該是什么？

select user_id,sum(score) as pointsfor,sum(X) as pointsagainst  group by user_id

Answer 1

我目前無法測試，但可以嘗試以下操作：

SELECT
  PointsFor.user_id, 
  sum(PointsFor.score) as pointsfor,
  sum(PointsAgainst.score) as pointsAgainst
FROM TABLE_NAME PointsFor
JOIN TABLE_NAME PointsAgainst
  on PointsFor.match_id = PointsAgainst.match_id
  and PointsFor.user_id <> PointsAgainst.user_id
GROUP BY PointsFor.user_id

觀察員：用您的表的實際名稱替換上面的TABLE_NAME 。

Answer 2

你可以試試看

select user_id, sum(score) as pointsfor,
    (select sum(score) 
      from tab b 
      where a.match_id=b.match_id and a.user_id !=b.user_id) as pointsagainst 
from tab a
group by user_id

Answer 3

知道分數是贊成還是反對的唯一方法是比較分數。

我將使用子查詢來首先確定點，然后對每個用戶進行總結：（假設您的表名是“點”）：

select user_id, SUM(pointsfor) as PointsFor, SUM(pointsagainst) as PointsAgainst, SUM(pointstied) as PointsTied
from (
    select a.user_id, case when a.score > b.score then a.score else 0 end as PointsFor,
    case when a.score < b.score then a.score else 0 end as PointsAgainst,
    case when a.score = b.score then a.score else 0 end as PointsTied
    from points a
    join Points b on a.match_id = b.match_id and a.user_id != b.user_id
) sub
group by sub.user_id