获得总计数和子集计数的最简单方法? [英] Easiest way to get a total count and a count of a subset?

问题描述

我试图这样做:

SELECT COUNT(*),
        (
            SELECT COUNT(*) FROM attend
            WHERE (DATEPART(WEEKDAY,start_date) = 2 OR DATEPART(WEEKDAY,start_date) = 6)
            AND empl_no = 12345
        )
        FROM attend as a
 WHERE empl_no = 12345

但这似乎有点难看.有没有更好的方法来做到这一点?

But this seems a little ugly. Is there a better way to do this?

推荐答案

您可以使用 CTE:

WITH T1 AS (
    SELECT DATEPART(WEEKDAY,start_date) AS weekday
    FROM attend
    WHERE empl_no = 12345
)
SELECT
    (SELECT COUNT(*) FROM T1) AS total,
    (SELECT COUNT(*) FROM T1 WHERE weekday = 2 OR weekday = 6) AS subset

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