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  • 一个SQL语句的变化过程

    1  原始语句

    SELECT C.ParentId,A.Area_DM, A.Airport_DM, ('        ' + B.QC) AS AirportName,Sum(JCN) AS TotalJCN, 
    SUM(CR + ET + CRWH + ETWH)  AS TotalLK, Sum(HW + YJ)  AS TotalHY, Sort = 1 
    FROM AirportProduces_2006 A 
    LEFT JOIN Airports B ON A.Airport_DM = B.Airport_DM 
    LEFT JOIN Areas AS C ON C.Area_DM = A.Area_DM
    LEFT JOIN HBXZ AS D ON A.HBXZ = D.CHAR_CODE
    WHERE A.Produce_Date >= '2006-01-01' AND A.Produce_Date <= '2006-02-28'
    AND D.CHAR_SORT = '运输'
    AND  (A.Area_DM = '51')  GROUP BY A.Area_DM, A.Airport_DM, B.QC, C.ParentId,D.CHAR_SORT

    2 变化要求:当Sum(JCN)的时候不考虑where条件中的D.CHAR_SORT

       变化第一步:

    SELECT C.ParentId,A.Area_DM, A.Airport_DM, ('        ' + B.QC) AS AirportName,Sum(JCN) AS TotalJCN, 
    CASE WHEN D.CHAR_SORT = '运输' THEN SUM(CR + ET + CRWH + ETWH) ELSE 0 END AS TotalLK, 
    CASE WHEN D.CHAR_SORT = '运输' THEN Sum(HW + YJ) ELSE 0 END AS TotalHY, Sort = 1 INTO #TEMP
    FROM AirportProduces_2006 A 
    LEFT JOIN Airports B ON A.Airport_DM = B.Airport_DM 
    LEFT JOIN Areas AS C ON C.Area_DM = A.Area_DM
    LEFT JOIN HBXZ AS D ON A.HBXZ = D.CHAR_CODE
    WHERE A.Produce_Date >= '2006-01-01' AND A.Produce_Date <= '2006-02-28'
    AND (A.Area_DM = '51') GROUP BY A.Area_DM, A.Airport_DM, B.QC, C.ParentId,D.CHAR_SORT


    SELECT ParentId,Area_DM,Airport_DM,AirportName, 
    SUM(TotalJCN) AS TotalJCN,SUM(TotalLK) AS TotalLK,SUM(TotalHY) AS TotalHY,Sort = 1 FROM #TEMP2 
    GROUP BY Area_DM, Airport_DM, ParentId, AirportName

    这个步骤运用临时表  将结果放入临时表 然后再分组统计


    2 演化步骤二

    综合第一步,可以写出第二步,一条语句

    SELECT ParentId,Area_DM,Airport_DM,AirportName, 
    SUM(TotalJCN) AS TotalJCN,SUM(TotalLK) AS TotalLK,SUM(TotalHY) AS TotalHY,Sort = 1 FROM (
    SELECT C.ParentId,A.Area_DM, A.Airport_DM, ('        ' + B.QC) AS AirportName,
    Sum(JCN) AS TotalJCN, 
    CASE WHEN D.CHAR_SORT = '运输' THEN SUM(CR + ET + CRWH + ETWH) ELSE 0 END AS TotalLK, 
    CASE WHEN D.CHAR_SORT = '运输' THEN Sum(HW + YJ) ELSE 0 END AS TotalHY, Sort = 1 FROM
    AirportProduces_2006 A 
    LEFT JOIN Airports B ON A.Airport_DM = B.Airport_DM 
    LEFT JOIN Areas AS C ON C.Area_DM = A.Area_DM
    LEFT JOIN HBXZ AS D ON A.HBXZ = D.CHAR_CODE
    WHERE A.Produce_Date >= '2006-01-01' AND A.Produce_Date <= '2006-02-28'
    AND (A.Area_DM = '51') GROUP BY A.Area_DM, A.Airport_DM, B.QC, C.ParentId,D.CHAR_SORT
    ) AS SUMTable GROUP BY Area_DM, Airport_DM, ParentId, AirportName
     

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  • 原文地址:https://www.cnblogs.com/tzy080112/p/1397743.html
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