Question

我正在使用Microsoft SQL Server 2008 R2，我正在尝试比较运行以下相同查询的计数结果：

select 
    e.JobTitle,
    COUNT(p.BusinessEntityID) [NO. of persons]
from 
    AdventureWorks2008.person.Person p with (Nolock)
join 
    AdventureWorks2008.HumanResources.Employee e with (nolock) on e.BusinessEntityID = p.BusinessEntityID
group by 
    e.JobTitle

我按预期得到以下结果：

JobTitle                        NO. Of persons
Accountant                                   2
Accounts Manager                             1
Accounts Payable Specialist                  2
Accounts Receivable Specialist               3
Application Specialist                       4
Assistant to the Chief Financial Officer     1
Benefits Specialist                          1
Buyer                                        9
Chief Executive Officer                      1
Chief Financial Officer                      1
Control Specialist                           2
Database Administrator                       2
Design Engineer                              3
Document Control Assistant                   2
Document Control Manager                     1
Engineering Manager                          1

我现在要做的是显示职位名称并从这些结果中计算，其中计数相同，但职位名称不同。

基本上买方不会被退回，因为没有其他组的数量为9。

但首席财务官助理，福利专家等将被退回，因为有许多职位，数量为1。

最简单，最有效的方法是什么？谢谢你。

Answer 1

您可以使用cte：

执行此操作

<uses-permission>

Answer 2

您可以使用join搜索具有相同计数但具有不同职位的其他行：

; with  List as 
        (
        ... your query here ...
        )
select  *
from    List l1
join    List l2
on      l1.[NO. of persons] = l2.[NO. of persons]
        and l1.JobTitle > l2.JobTitle -- Filter out duplicates

Answer 3

您可以使用窗口功能：

select *
from (select e.JobTitle,
             COUNT(p.BusinessEntityID) as [NO. of persons],
             COUNT(*) OVER (PARTITION BY COUNT(*)) as count_with_count
     from AdventureWorks2008.person.Person p with (Nolock) join 
          AdventureWorks2008.HumanResources.Employee e with (nolock) 
          on e.BusinessEntityID = p.BusinessEntityID
     group by e.JobTitle
    ) jt
where count_with_count > 1
order by count_with_count;

比较来自同一表的计数数据

3 个答案: