Question

我有一个查询，对于每个操作系统，它提供计算机的总数，程序XYZ的总数，不需要程序XYZ的总数，以及缺少程序XYZ的总数（这是所有没有的人程序XYZ并不是免税的）。我的数据在两个表中，我希望我可以使用联合将数据折叠成一个结果。这就是我的意思：

SELECT [OS Name],
(SELECT COUNT (DISTINCT statement for total computers including a few joins and where))
(SELECT COUNT (DISTINCT statement for installed including a few joins and where))
(SELECT COUNT (DISTINCT statement for exempt including a few joins and where))
(SELECT COUNT (DISTINCT statement for missing including a few joins and where and a subquery))
FROM table

如果它有用，我可以发布真实的查询。每个SELECT都是SELECT COUNT（DISTINCT Guid）FROM表JOIN table2 JOIN table3 WHERE condition1和condition2，其中一些在WHERE语句中使用子查询。

它会返回如下结果：

OS Name Total computers for this OS Program Installed   Exempt  Missing Program
Microsoft Windows XP    4776    819 12  3955
Windows 7 Enterprise    4   1   1   2

第二个查询针对不同的数据库运行：

OS Name Total computers for this OS Program Installed   Exempt  Missing Program
Microsoft Windows XP    42  7   0   36
Windows 7 Enterprise    2196    2143    21  33

我希望简单地在这两者之间添加一个UNION会增加数字，我的数据将有两行，而是有4行 - 每个操作系统列出两次，每个数据库一次。

我搜索了Google和Stackoverflow，没有运气。

像SQL Count(*) on multiple tables这样的线程 two SQL COUNT() queries?似乎是正确的方法，但由于我的COUNT很复杂，我正在努力解决如何使用它的问题。对于一个简单的列名，它不是COUNT（emp_id），而是使用JOIN，条件，有时是子查询。

Answer 1

使用您的联盟，但您需要根据这些结果进一步汇总。查询近似值。

SELECT
    D.[OS Name]
,   SUM(D.[Computer Count]) AS [Computer Count]
,   D. ...
FROM
(
SELECT [OS Name],
(SELECT COUNT (DISTINCT statement for total computers including a few joins and where))
(SELECT COUNT (DISTINCT statement for installed including a few joins and where))
(SELECT COUNT (DISTINCT statement for exempt including a few joins and where))
(SELECT COUNT (DISTINCT statement for missing including a few joins and where and a subquery))
FROM table

UNION ALL
SELECT [OS Name],
(SELECT COUNT (DISTINCT statement for total computers including a few joins and where))
(SELECT COUNT (DISTINCT statement for installed including a few joins and where))
(SELECT COUNT (DISTINCT statement for exempt including a few joins and where))
(SELECT COUNT (DISTINCT statement for missing including a few joins and where and a subquery))
FROM table2
) D
GROUP BY
    D.[OS Name]

用于多列查询的SQL COUNT UNION

1 个答案: