Question

我有查询需要很长时间才能执行

SELECT 
    cft.ID, cft.Name AS 'CauseArea' , COUNT(DISTINCT e.ID) AS 'Donors',
    SUM(CASE WHEN d.DonationType = 1 THEN d.Amount ELSE 0 END) AS 'DonationsForAvarage' ,
    SUM(CASE WHEN d.DonationType = 1 THEN d.Amount ELSE 0 END) AS 'EmployeeDonations' ,
   SUM(CASE WHEN d.DonationType = 2 THEN d.Amount ELSE 0 END) AS 'MatchedDonations' ,
   SUM(CASE WHEN d.DonationType = 1 OR d.DonationType = 2 THEN d.Amount ELSE 0 END) AS 'TotalDonations'
FROM 
    dbo.Donation d
INNER JOIN 
    dbo.Employee e ON e.ID = d.Employee
INNER JOIN 
    CharityProjectDetails cpd ON d.CharityProjectDetails = cpd.ID
INNER JOIN 
    CharityDetails cd ON cpd.CharityDetails = cd.ID
INNER JOIN 
    CauseFocusType cft ON cd.CauseFocusType = cft.ID
GROUP BY 
    cft.ID, cft.Name

所以我注意到DISTINCT是食客。我想摆脱DISTINCT - 我该怎么做？

Answer 1

我使用子查询为捐赠表做了。如果这对您有任何帮助，请检查一下。

        SELECT cft.ID
,cft.NAME AS 'CauseArea'
,d.cnt AS 'Donors'
,SUM(CASE 
        WHEN d.DonationType = 1
            THEN d.Amount
        ELSE 0
        END) AS 'DonationsForAvarage'
,SUM(CASE 
        WHEN d.DonationType = 1
            THEN d.Amount
        ELSE 0
        END) AS 'EmployeeDonations'
,SUM(CASE 
        WHEN d.DonationType = 2
            THEN d.Amount
        ELSE 0
        END) AS 'MatchedDonations'
,SUM(CASE 
        WHEN d.DonationType = 1
            OR d.DonationType = 2
            THEN d.Amount
        ELSE 0
        END) AS 'TotalDonations'
FROM (SELECT  Employee
             ,DonationType
             ,CharityProjectDetails
             ,Amount
             ,COUNT(Employee) as cnt 
      FROM dbo.Donation
      GROUP BY Employee
             ,DonationType
             ,CharityProjectDetails
             ,Amount) d
INNER JOIN CharityProjectDetails cpd ON d.CharityProjectDetails = cpd.ID
INNER JOIN CharityDetails cd ON cpd.CharityDetails = cd.ID
INNER JOIN CauseFocusType cft ON cd.CauseFocusType = cft.ID
GROUP BY cft.ID
,cft.NAME

Answer 2

看起来dbo.Employee上的INNER JOIN不是必需的，因为你已经拥有dbo.Donation中的数据。试试这个：

SELECT cft.ID
,cft.NAME AS 'CauseArea'
,COUNT(DISTINCT d.Employee) AS 'Donors'
,SUM(CASE 
        WHEN d.DonationType = 1
            THEN d.Amount
        ELSE 0
        END) AS 'DonationsForAvarage'
,SUM(CASE 
        WHEN d.DonationType = 1
            THEN d.Amount
        ELSE 0
        END) AS 'EmployeeDonations'
,SUM(CASE 
        WHEN d.DonationType = 2
            THEN d.Amount
        ELSE 0
        END) AS 'MatchedDonations'
,SUM(CASE 
        WHEN d.DonationType = 1
            OR d.DonationType = 2
            THEN d.Amount
        ELSE 0
        END) AS 'TotalDonations'
FROM dbo.Donation d
INNER JOIN CharityProjectDetails cpd ON d.CharityProjectDetails = cpd.ID
INNER JOIN CharityDetails cd ON cpd.CharityDetails = cd.ID
INNER JOIN CauseFocusType cft ON cd.CauseFocusType = cft.ID
GROUP BY cft.ID
,cft.NAME

如何在sql查询中删除Distinct

2 个答案: