在WHERE子句中使用CASE - 數據參數Sql Server

我想驗證示例，如果日期爲null，則從另一個字段中選擇一個日期。下面的查詢：在WHERE子句中使用CASE - 數據參數Sql Server

SELECT 
    * 
FROM 
    OrderPublish OP 
    INNER JOIN Advertising AD ON 
     AD.IdOrderPublish = OP.IdOrderPublish 
    INNER JOIN Client Cli ON 
     Cli.IdClient = OP.IdClient 
    LEFT JOIN AdvertisingInserted AII ON 
     AD.IdAdvertisingInserted = AII.IdAdvertisingInserted 
    LEFT JOIN TypeProduct TP ON 
     AII.IdTypeProduct = TP.IdTypeProduct 
    INNER JOIN Publication PUB ON 
     PUB.IdAdvertisingInserted = AII.IdAdvertisingInserted 
WHERE 
    TP.IdTypeProduct in (5,7) 
    AND CASE WHEN PUB.DtIni IS NULL 
     THEN 
      OP.DtInc >= Isnull('08/18/2013', OP.DtInc) 
     ELSE 
      PUB.DtIni >= Isnull('08/18/2013', PUB.DtIni) 
     END 
    AND CASE PUB.DtFinal WHEN NULL 
     THEN 
      OP.DtInc <= Isnull('08/23/2013', OP.DtInc) 
     ELSE 
      PUB.DtFinal <= Isnull('08/23/2013', PUB.DtFinal) 
     END

來源

2013-08-26 D. Scott

親愛的，如果AII爲空（LEFT OUTER JOIN失敗）當您使用INNER同一AII表時，你失去了你的行。你確定？ –

你可以在你的情況與COALESCE()做到這一點，但如果你想使用CASE在WHERE標準，你可以這樣做。移動CASE語句之外的匹配條件，您需要CASE語句返回要比較的值，而不是比較本身。這需要增加了一倍每個CASE聲明：

SELECT 
    * 
FROM 
    OrderPublish OP 
    INNER JOIN Advertising AD ON 
     AD.IdOrderPublish = OP.IdOrderPublish 
    INNER JOIN Client Cli ON 
     Cli.IdClient = OP.IdClient 
    LEFT JOIN AdvertisingInserted AII ON 
     AD.IdAdvertisingInserted = AII.IdAdvertisingInserted 
    LEFT JOIN TypeProduct TP ON 
     AII.IdTypeProduct = TP.IdTypeProduct 
    INNER JOIN Publication PUB ON 
     PUB.IdAdvertisingInserted = AII.IdAdvertisingInserted 
WHERE 
    TP.IdTypeProduct in (5,7) 
    AND CASE WHEN PUB.DtIni IS NULL 
     THEN 
      OP.DtInc 
     ELSE 
      PUB.DtIni 
     END 
    >= CASE WHEN PUB.DtIni IS NULL 
     THEN 
      Isnull('08/18/2013', OP.DtInc) 
     ELSE 
      Isnull('08/18/2013', PUB.DtIni) 
     END 

    AND CASE PUB.DtFinal WHEN NULL 
     THEN 
      OP.DtInc 
     ELSE 
      PUB.DtFinal 
     END 
    <= CASE PUB.DtFinal WHEN NULL 
     THEN 
      Isnull('08/23/2013', OP.DtInc) 
     ELSE 
      Isnull('08/23/2013', PUB.DtFinal) 
     END

這就是你可以在你的WHERE標準使用CASE語句，但你可以使用AND()和OR()標準與COALESCE()一起做這個而不CASE

而且，您的ISNULL()陳述是向後，'08/18/2013'將永遠不會NULL，所以該字段將不會被評估，您可能的意思是：Isnull(OP.DtInc,'08/23/2013')

來源

2013-08-26 15:31:43

相反情況下，你可以嘗試合併功能：http://msdn.microsoft.com/en-us/library/ms190349.aspx

SELECT 
    * 
FROM 
    OrderPublish OP 
    INNER JOIN Advertising AD ON 
     AD.IdOrderPublish = OP.IdOrderPublish 
    INNER JOIN Client Cli ON 
     Cli.IdClient = OP.IdClient 
    LEFT JOIN AdvertisingInserted AII ON 
     AD.IdAdvertisingInserted = AII.IdAdvertisingInserted 
    LEFT JOIN TypeProduct TP ON 
     AII.IdTypeProduct = TP.IdTypeProduct 
    INNER JOIN Publication PUB ON 
     PUB.IdAdvertisingInserted = AII.IdAdvertisingInserted 
WHERE 
    TP.IdTypeProduct in (5,7) 
    AND Coalesce(PUB.DtIni,OP.DtInc)>= Isnull('08/18/2013', OP.DtInc) 
    AND Coalesce(PUB.DtFinal,OP.DtInc)<= Isnull('08/23/2013', OP.DtInc)

來源

2013-08-26 15:32:17 Sonam

在WHERE子句中使用CASE - 數據參數Sql Server

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