计算组中的额外列

Question

确定这应该很简单，但我有brain fart。

在SQL Server 2005中，如何为GROUP BY查询添加“额外计数”？

考虑以下内容......

;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，总计ACTIONNEEDED=1 ...

的行数

TYPEID  TOTAL ACTIONNEEDED
1       2     0
2       3     1

注意：遗憾的是由于项目限制，我仅限于SQL Server 2005兼容的答案

Answer 1

您可以将SUM与内部CASE声明一起使用：

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