如何使用聚合函数过滤 SQL 语句中的行

Question

我在 SQL 中创建了一个 [Total Calls Made] 列，但不知道如何访问它。我试图只显示 [Total Calls Made] 等于 0 的行，但由于它实际上不是 table 的一部分，我不能只添加一个说 where [Total Calls Made] = 0 的子句。我尝试添加 having count(distinct f.[id])=0，但所做的只是使 Total Call Made 中的非 0 值变为 Null。这是为什么？我只能对 select 0 行做什么？

SQL:

select 
    p.[ref] as [ID],
    p.[first] as [First],
    (select count(distinct f.[id]) 
     from [field] f 
     where (f.[related] = p.[id]) 
       and (f.[field] = 'person_that_called') 
     having count(distinct f.[id]) > 0) as [Total Calls Made]
from 
    [person] p

结果：

ID     First   Total Calls Made
--- |  ----  | ----------------
011 |  Bob   |       4
012 |  Susan |       2
013 |  Joe   |      Null

期望的结果：

ID     First   Total Calls Made
--- |  ----  | ----------------
013 |  Joe   |        0

使用连接使所有非 0 值不显示，这与我想要的相反。

Answer 1

SELECT p.[Ref] as [ID], p.[First] as [First], Count(f.[Field]) as CallsMade 
from [person] p 
left outer join [field] f on f.[Related] = p.[Ref] and f.[Field] = 'person_that_called'
group by p.[Ref], p.[First]
having Count(f.[Field]) =0

这就是你想要的吗？

Answer 2

尝试使用 cte

WITH    cte
      AS (SELECT    p.[ref] AS [ID]
                   ,p.[first] AS [First]
                   ,(SELECT  COUNT(DISTINCT f.[id])
                            FROM    [field] f
                            WHERE   (f.[related] = p.[id])
                                    AND (f.[field] = 'person_that_called')
                            HAVING  COUNT(DISTINCT f.[id]) > 0
                           ) AS [Total Calls Made]
          FROM      [person] p
         )
SELECT  [ID]
       ,[First]
       ,ISNULL([Total Calls Made],0) as [Total Calls Made]
FROM    cte
WHERE   ISNULL(cte.[Total Calls Made],0) = 0

如何使用聚合函数过滤 SQL 语句中的行

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