SQl服务器查询多个聚合列

Question

我需要在sql server中编写一个查询数据就像这样。

基本上它是由部门，种族，性别分组然后

SUM(employees_of_race_by_gender),Sum(employees_Of_Dept).

我可以获得前四列的数据，获得该部门的员工总数变得越来越困难。 你能帮我写一下这个问题吗？

所有这些细节在同一张表中。 Emp的列是Emp_Number，Race_Name，Gender，Dept

Answer 1

您的“num_of_emp_in_race”实际上也属于性别

SELECT DISTINCT
    Dept,
    Race_name,
    Gender,
    COUNT(*) OVER (PARTITION BY Dept, Race_name, Gender) AS num_of_emp_in_race,
    COUNT(*) OVER (PARTITION BY Dept) AS num_of_emp_dept
FROM
    MyTable

你应该有这个

    COUNT(*) OVER (PARTITION BY Dept, Gender) AS PerDeptRace
    COUNT(*) OVER (PARTITION BY Dept, Race_name) AS PerDeptGender,
    COUNT(*) OVER (PARTITION BY Dept, Race_name, Gender) AS PerDeptRaceGender,
    COUNT(*) OVER (PARTITION BY Dept) AS PerDept

修改：DISTINCT似乎在COUNT（would odd based on this）之前应用，因此请尝试此操作

SELECT DISTINCT
    *
FROM
    (
    SELECT 
        Dept,
        Race_name,
        Gender,
        COUNT(*) OVER (PARTITION BY Dept, Race_name, Gender) AS num_of_emp_in_race,
        COUNT(*) OVER (PARTITION BY Dept) AS num_of_emp_dept
    FROM
        MyTable
    ) foo

Answer 2

由于您要查找的两个总和基于不同的聚合，因此您需要单独计算它们并加入结果。在这种情况下，我首先构建选择以向我显示不同的结果，以便尽早发现错误：

SELECT Dept, Gender, race_name, COUNT(*) as num_of_emp_in_race
FROM Emp
GROUP BY 1, 2, 3

SELECT Dept, COUNT(*) as num_of_emp_in_dept
FROM Emp
GROUP BY 1

之后，加入这两者非常简单：

SELECT * 
FROM ( first statement here ) as by_race
JOIN ( second statement here ) as by_dept ON (by_race.Dept = by_dept.Dept)