多列的大小写和总和

Question

在我的数据库中，我有几千名客户，某些标准以不同的时间间隔发生。一周中的每一天都有列（M，Tu，W，Th，F，Sa，Su）。我需要查看每周有多少天会触发任务。我有下面的查询，但它当然也会返回一周中的特定日期以及每周的 TotalDays。但是，我只需要查看 TotalDays 而不是每天的额外显示。我怎样才能做到这一点？

SELECT X.*,M+Tu+W+Th+F+Sa+Su AS TotalDays
FROM
    (
    SELECT
        CASE WHEN [M] = '1' THEN 1 ELSE 0 END as "M",
        CASE WHEN [Tu] = '1' THEN 1 ELSE 0 END as  "Tu",
        CASE WHEN [W] = '1' THEN 1 ELSE 0 END as "W",
        CASE WHEN [Th] = '1' THEN 1 ELSE 0 END as  "Th",
        CASE WHEN [F] = '1' THEN 1 ELSE 0 END as "F",
        CASE WHEN [Sa] = '1' THEN 1 ELSE 0 END as  "Sa",
        CASE WHEN [Su] = '1' THEN 1 ELSE 0 END as "Su"
    FROM
        Customers
    ) X

我应该说这里的数据类型是位，所以我不能只做如下的总和，因为这会返回数据类型位对求和运算符无效的错误。

SELECT 
 (SUM(M) + SUM(Tu) + SUM(W) + SUM(Th) + SUM(F) + SUM(Sa) + SUM(Su)) as TotalDays
FROM Customers

Answer 1

这是你想要的吗？

SELECT SUM(CASE WHEN [M] = '1' THEN 1 ELSE 0 END +
           CASE WHEN [Tu] = '1' THEN 1 ELSE 0 END +
           CASE WHEN [W] = '1' THEN 1 ELSE 0 END +
           CASE WHEN [Th] = '1' THEN 1 ELSE 0 END +
           CASE WHEN [F] = '1' THEN 1 ELSE 0 END +
           CASE WHEN [Sa] = '1' THEN 1 ELSE 0 END +
           CASE WHEN [Su] = '1' THEN 1 ELSE 0 END
          )
FROM Customers;