计算组中的额外列

Question

当然这应该很简单，但我有一个brain fart。

在 SQL Server 2005 中，如何将 "extra count" 添加到 GROUP BY 查询？

考虑以下...

;WITH DATA AS (
    SELECT 1 AS ID, 1 AS TYPEID, 0 AS ACTIONNEEDED 
    UNION
    SELECT 2 AS ID, 1 AS TYPEID, 0 AS ACTIONNEEDED 
    UNION
    SELECT 3 AS ID, 2 AS TYPEID, 0 AS ACTIONNEEDED 
    UNION
    SELECT 4 AS ID, 2 AS TYPEID, 1 AS ACTIONNEEDED 
    UNION
    SELECT 5 AS ID, 2 AS TYPEID, 0 AS ACTIONNEEDED 
)
SELECT TYPEID, COUNT(*) AS TOTAL
FROM DATA
GROUP BY TYPEID

结果是……

TYPEID  TOTAL
1       2
2       3

但我需要的是一个额外的列，它总计 ACTIONNEEDED=1...

的行数

TYPEID  TOTAL ACTIONNEEDED
1       2     0
2       3     1

注意：不幸的是，由于项目限制，我只能使用 SQL Server 2005 兼容的答案

Answer 1

您可以将 SUM 与内部 CASE 语句一起使用：

SELECT 
    TYPEID, 
    COUNT(*) AS TOTAL, 
    SUM(CASE WHEN ActionNeeded = 1 THEN 1 ELSE 0 END) AS ACTIONNEEDED
FROM DATA
GROUP BY TYPEID

计算组中的额外列

Calculate extra column in group by

sql-server

group-by

sql-server-2005