如何在sql脚本中执行减法功能

Question

我需要编写一个sql脚本，用于在每个月初开始赎回后计算我们的客户剩余点数。但我不太确定SQL查询和SQL脚本。 我写了两个查询来计算赚取和花费的积分。为了获得总积分：

select Tbl_member.member_id,sum(points_earned) 
    from Tbl_member, Tbl_member_participation 
    where tbl_member_participation.member_id = Tbl_member.member_id 
    group by Tbl_member.member_id, 

和点花：

select Tbl_member.member_id,sum(points_redeemed) 
    from Tbl_member, Tbl_member_redemption 
    where tbl_member_redemption.member_id = Tbl_member.member_id 
    group by Tbl_member.member_id 

我想从获得的积分减去废点，但我不知道如何将其合并成一个劲儿地输出sql脚本。以及如何使这个运行每个月。

Answer 1

试试这个

SELECT Tbl_member.member_id, 
     Sum(points_earned) - Sum(points_redeemed) Remaining_points 
FROM Tbl_member 
     JOIN Tbl_member_participation 
     ON tbl_member_participation.member_id = Tbl_member.member_id 
     JOIN Tbl_member_redemption 
     ON tbl_member_redemption.member_id = Tbl_member.member_id 
GROUP BY Tbl_member.member_id, 
      Datepart(mm, datecol), 
      Datepart(yyyy, datecol) 

Answer 2

您可以简单地使用UNION函数来组合两个查询结果。 此查询未经过测试，但这些是您可以使用UNION简单播放两个查询的方式。

SELECT 
    member_id, 
    SUM(points_earned) - SUM(points_redeemed) 
FROM 
(
    SELECT 
     Tbl_member.member_id, 
     sum(points_earned) points_earned, 
     0 AS points_redeemed 
    FROM 
     Tbl_member, 
     Tbl_member_participation 
    WHERE 
    tbl_member_participation.member_id = Tbl_member.member_id 
    GROUP BY 
    Tbl_member.member_id 


    UNION ALL 

    select 
     Tbl_member.member_id, 
     0 AS points_earned, 
     sum(points_redeemed) points_redeemed 
    from 
     Tbl_member, Tbl_member_redemption 
    where 
     tbl_member_redemption.member_id = Tbl_member.member_id 
    group by 
     Tbl_member.member_id 

) as 
a 
GROUP BY 
member_id 

Answer 3

你正在做CROSS JOIN，这不是你想要的（from Tbl_member, Tbl_member_participation）。改为使用LEFT JOIN或INNER JOIN。

SQL脚本可以包含多个查询和其他命令，如FOR等，也可以包含GO语句。从你的角度来看，这并不重要。

SELECT m.member_id, SUM(mr.points_redeemed), SUM (mp.points_earned), 
     ISNULL(SUM(mp.points_earned),0) - ISNULL(SUM(mr.points_redeemed),0) as Result 
    FROM Tbl_member m 
    LEFT JOIN Tbl_member_redemption mr ON mr.member_id = m.member_id 
    LEFT JOIN Tbl_member_participation mp ON mp.member_id = m.member_id 
    GROUP BY m.member_id 

您可以通过一个查询来实现您的目标。 如果你想为个别月份的结果，只需添加一个标准的GROUP BY这样的：

GROUP BY m.member_id, MONTH(nameOfDateColumn), YEAR(nameOfDateColumn) 

Answer 4

，如果你不关心该查询应显示行的所有成员，那么你可以删除喜欢

SELECT p.member_id, 
     Sum(points_earned), 
     Sum(points_redeemed), 
     Sum(CASE 
      WHEN points_earned IS NULL THEN 0 
      ELSE points_earned 
      END) - Sum(CASE 
         WHEN points_redeemed IS NULL THEN 0 
         ELSE points_redeemed 
         END) AS diff 
FROM Tbl_member_participation p 
     LEFT OUTER JOIN tbl_member_redemption r 
        ON p.member_id = r.member_id 
GROUP BY p.member_id 

加入的成员表，否则使用：

SELECT m.member_id, 
     Sum(points_earned), 
     Sum(points_redeemed), 
     Sum(CASE 
      WHEN points_earned IS NULL THEN 0 
      ELSE points_earned 
      END) - Sum(CASE 
         WHEN points_redeemed IS NULL THEN 0 
         ELSE points_redeemed 
         END) AS diff 
FROM Tbl_member m 
     LEFT OUTER JOIN Tbl_member_participation p 
        ON m.member_id = p.member_id 
     LEFT OUTER JOIN tbl_member_redemption r 
        ON m.member_id = r.member_id 
GROUP BY m.member_id ; 

，如果你想找到的差异月明智然后

SELECT m.member_id,datepart(mm,p.earndate),datepart(yyyy,p.earndate), 
     Sum(points_earned), 
     Sum(points_redeemed), 
     Sum(CASE 
      WHEN points_earned IS NULL THEN 0 
      ELSE points_earned 
      END) - Sum(CASE 
         WHEN points_redeemed IS NULL THEN 0 
         ELSE points_redeemed 
         END) AS diff 
FROM Tbl_member m 
     LEFT OUTER JOIN Tbl_member_participation p 
        ON m.member_id = p.member_id 
     LEFT OUTER JOIN tbl_member_redemption r 
        ON m.member_id = r.member_id and p.earndate = r.redeemdate 
GROUP BY m.member_id,datepart(mm,p.earndate),datepart(yyyy,p.earndate) 

here是SQL小提琴演示