如何将此SQL查询转换为MS Access查询？

Question

我在SQL中有Query

SELECT        COUNT(DISTINCT dbo.Polling_Stations.P_ID) AS [Male Stations]
FROM            dbo.Agent INNER JOIN
                     dbo.Polling_Stations ON dbo.Agent.P_ID = dbo.Polling_Stations.P_ID
GROUP BY dbo.Polling_Stations.Gender
HAVING        (dbo.Polling_Stations.Gender = N'Male')

我已将其转换为Access为:

SELECT        COUNT(DISTINCT Polling_Stations.P_ID) AS [Male Stations]
FROM            Agent INNER JOIN
                     Polling_Stations ON Agent.P_ID = Polling_Stations.P_ID
GROUP BY Polling_Stations.Gender
HAVING        (Polling_Stations.Gender = 'Male') 

但它给了我一个错误:查询表达式'Count(DISTINCT Polling_Stations.P_ID)'中的语法错误(缺少运算符).

Answer 1

Access SQL不支持COUNT(DISTINCT ...),因此您需要这样做

SELECT COUNT(*) AS [Male Stations]
FROM
(
    SELECT DISTINCT Polling_Stations.P_ID
    FROM Agent INNER JOIN Polling_Stations 
        ON Agent.P_ID = Polling_Stations.P_ID
    WHERE Polling_Stations.Gender = "Male"
)