Question

有人能弄明白如何摆脱NOT EXISTS条款中的WHERE陈述吗？

SELECT TOP 100 PERCENT 
    Ftm.AcctID AS [Acct Id], 
    Act.AccountNumber AS [Account No.], 
    Act.AccountTypeId, 
    ISNULL(Cnt.FirstName, '')+ ' ' + ISNULL(Cnt.LastName, '') AS [Full Name], 
    Ftm.FinTransTypeCode AS [Trans Type], 
    Ftm.FinTransCode AS [Trans Code], 
    Fm.FJNo AS [FJ No.],   
    Fm.ReversalFJNo  AS [Reversal FJNo.],  
    CAST(ISNULL(Fm.FJAmt,0) AS DECIMAL(9, 2))  AS Amount, 
    Ftc.InterfaceDescr AS [Transaction Desc], 
    Fm.Comments, Fm.CreatedBy AS [Posted By],   
    Ftm.Created,RegistrationTypeid, FJDate  
FROM
    FinMaster AS Fm 
    INNER JOIN FinTransMaster AS Ftm ON Ftm.FjNo = Fm.FJNo 
    INNER JOIN dbo.Account AS Act ON Ftm.AcctID = Act.AccountId
    INNER JOIN dbo.Contact AS Cnt ON Act.PrimaryContactId = Cnt.ContactId
    INNER JOIN FinTransCodes AS Ftc ON Ftc.FinTransCode = Ftm.FinTransCode
WHERE     
    (Ftm.FinTransTypeCode <> 'PYMT') AND FJDate > getdate()-5  
    AND (NOT EXISTS (SELECT '' AS Expr1  
                     FROM FinMaster  
                     WHERE (ReversalFjNo = Fm.FJNo))) 
    AND (NOT EXISTS (SELECT '' AS Expr1  
                     FROM FinTransMaster AS Ftm2  
                     WHERE (FjNo = Ftm.FjNo) AND (FjTransSeqNo < Ftm.FjTransSeqNo)))  
ORDER BY Ftm.Created DESC

Answer 1

在SQL Server中，NOT IN / NOT EXISTS 比LEFT JOIN更好 ，因为它的优化器无法在LEFT JOIN / IS NULL中识别ANTI JOIN。它将返回整个结果集，然后过滤掉NULL。

WITH contacts AS (
     SELECT t.contactid,
            CASE
              WHEN t.firstname IS NULL AND t.lastname IS NULL THEN
                ''
              WHEN t.firstname IS NULL THEN
                t.lastname
              WHEN t.lastname IS NULL THEN
                t.firstname
              ELSE
                t.FirstName + ' ' t.LastName
           END AS [fullname]
      FROM dbo.CONTACT t)
SELECT TOP 100 PERCENT 
       ftm.AcctID AS [Acct Id], 
       a.AccountNumber AS [Account No.], 
       a.AccountTypeId, 
       c.fullname AS [Full Name], 
       ftm.FinTransTypeCode AS [Trans Type], 
       ftm.FinTransCode AS [Trans Code], 
       t.FJNo AS [FJ No.],   
       t.ReversalFJNo  AS [Reversal FJNo.],  
       CAST(ISNULL(t.FJAmt, 0) AS DECIMAL(9, 2)) AS Amount, 
       ftc.InterfaceDescr AS [Transaction Desc], 
       t.Comments,
       t.CreatedBy AS [Posted By],   
       ftm.Created,
       RegistrationTypeid,
       FJDate  
 FROM FINMASTER t
 JOIN FINTRANSMASTER ftm ON ftm.FjNo = t.FJNo 
                        AND ftm.FinTransTypeCode <> 'PYMT'
 JOIN dbo.ACCOUNT a ON a.accountid = ftm.AcctID 
 JOIN contacts c ON c.contactid = a.PrimaryContactId
 JOIN FINTRANSCODES ftc ON ftc.FinTransCode = ftm.FinTransCode
WHERE FJDate > getdate()-5  
  AND NOT EXISTS (SELECT NULL  
                    FROM FinMaster fm  
                   WHERE fm.ReversalFjNo = t.FJNo)
  AND NOT EXISTS (SELECT NULL
                    FROM FinTransMaster AS ftm2
                   WHERE ftm2.FjNo = ftm.FjNo 
                     AND ftm2.FjTransSeqNo < ftm.FjTransSeqNo)  
ORDER BY ftm.Created DESC

Answer 2

为什么要让自己接受这个？良好地使用子查询（特别是使用IN和NOT IN）使查询更具可读性，并且它们在大多数数据库引擎上都同样快。

通常，在要选择的表上使用JOIN，为其他所有内容使用子查询会导致最清晰的查询。这就是我的建议。

SELECT TOP 100 PERCENT 
    Ftm.AcctID AS [Acct Id], 
    Act.AccountNumber AS [Account No.], 
    Act.AccountTypeId, 
    ISNULL(Cnt.FirstName, '')+ ' ' + ISNULL(Cnt.LastName, '') AS [Full Name], 
    Ftm.FinTransTypeCode AS [Trans Type], 
    Ftm.FinTransCode AS [Trans Code], 
    Fm.FJNo AS [FJ No.],   
    Fm.ReversalFJNo  AS [Reversal FJNo.],  
    CAST(ISNULL(Fm.FJAmt,0) AS DECIMAL(9, 2))  AS Amount, 
    Ftc.InterfaceDescr AS [Transaction Desc], 
    Fm.Comments, Fm.CreatedBy AS [Posted By],   
    Ftm.Created,RegistrationTypeid, FJDate  
FROM
    FinMaster AS Fm 
    INNER JOIN FinTransMaster AS Ftm ON Ftm.FjNo = Fm.FJNo 
    INNER JOIN dbo.Account AS Act ON Ftm.AcctID = Act.AccountId
    INNER JOIN dbo.Contact AS Cnt ON Act.PrimaryContactId = Cnt.ContactId
    INNER JOIN FinTransCodes AS Ftc ON Ftc.FinTransCode = Ftm.FinTransCode
WHERE     
    (Ftm.FinTransTypeCode <> 'PYMT') AND FJDate > getdate()-5  
    AND Fm.FJNo NOT IN (
                     SELECT ReversalFjNo
                     FROM FinMaster  
                     WHERE ReversalFjNo IS NOT NULL) 
    AND Ftm.FjNo NOT IN (
                     SELECT FjNo
                     FROM FinTransMaster AS Ftm2  
                     WHERE FjNo IS NOT NULL) 
    AND (FjTransSeqNo < Ftm.FjTransSeqNo)))  
ORDER BY Ftm.Created DESC

Answer 3

我认为您可以在FinMaster和FinTransMaster表上执行OUTER JOIN，并使where子句指定这些表中的ID为空。

Answer 4

你只需要进行连接，其中null为空以下是使用您提供的查询的示例：

选择前100％
    Ftm.AcctID AS [Acct Id]，
    Act.AccountNumber AS [账号]，
    Act.AccountTypeId，
    ISNULL（Cnt.FirstName，''）+''+ ISNULL（Cnt.LastName，''）AS [全名]，
    Ftm.FinTransTypeCode AS [Trans Type]，
    Ftm.FinTransCode AS [Trans Code]，
    Fm.FJNo AS [FJ No.]，
    Fm.ReversalFJNo AS [Reversal FJNo。]，
    CAST（ISNULL（Fm.FJAmt，0）AS DECIMAL（9,2））AS金额，
    Ftc.InterfaceDescr AS [交易描述]，
    Fm.Comments，Fm.CreatedBy AS [发布者]，
    Ftm.Created，RegistrationTypeid，FJDate

来自FinMaster AS Fm
    INNER JOIN FinTransMaster AS Ftm ON Ftm.FjNo = Fm.FJNo
    INNER JOIN dbo.Account AS Act on Ftm.AcctID = Act.AccountId
    INNER JOIN dbo.Contact AS Cnt ON Act.PrimaryContactId = Cnt.ContactId
    INNER JOIN FinTransCodes AS Ftc ON Ftc.FinTransCode = Ftm.FinTransCode

left outer join FinMaster as FM2 on FM2.ReversalFjNo = Fm.FJNo and FM2.ReversalFjNo is null
left outer join FinTransMaster AS Ftm2 on (Ftm2.FjNo = Ftm.FjNo) AND (Ftm2.FjTransSeqNo < Ftm.FjTransSeqNo)
            and Ftm2.FjNo is null

WHERE
（Ftm.FinTransTypeCode＆lt;＆gt;'PYMT'）和FJDate＆gt; getdate（） - 5

按照Ftm.Created DESC订购

自联接而不是子查询

4 个答案: