PROSAGA码农传奇-plsql-SUM聚合函数问题

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   <pre>
    <code>
      create table SkuXFcst as
SELECT 21257 as item, 903 as loc, TO_DATE('2018-12-11')as startdate, 14400 as dur , 100 as qty from dual union all
SELECT 21257, 664, TO_DATE('2018-12-10'), 14400, 100 from dual union all
SELECT 11064, 101, TO_DATE('2018-11-26'), 43200, 300 from dual union all
SELECT 21257, 315, TO_DATE('2018-12-01'), 14400, 100 from dual union all
SELECT 21257, 314, TO_DATE('2018-12-10'), 14400, 100 from dual union all
SELECT 21257, 903, TO_DATE('2018-12-10'), 14400, 1000 from dual union all
SELECT 19510, 502, TO_DATE('2018-12-20'), 14400, 50  from dual union all
SELECT 19510, 502, TO_DATE('2018-12-20'), 14400, 500 from dual union all
SELECT 19507, 615, TO_DATE('2018-12-20'), 14400, 50  from dual union all
SELECT 19507, 615, TO_DATE('2018-12-22'), 14400, 50  from dual union all
SELECT 19510, 502, TO_DATE('2018-12-01'), 0    , 0   from dual ;

SELECT  item,
        loc,
        dur,
        SUM(CASE
              WHEN SkuXFcst.StartDate BETWEEN  to_date('2018-12-02','YYYY-MM-DD')    
                                      AND      to_date('2018-12-02','YYYY-MM-DD')+ 6 THEN SkuXFcst.Qty
              ELSE 0
            END) AS P1,
        SUM(CASE
              WHEN SkuXFcst.StartDate BETWEEN  to_date('2018-12-02','YYYY-MM-DD') + 7 
                                      AND      to_date('2018-12-02','YYYY-MM-DD') + 13 THEN SkuXFcst.Qty
              ELSE 0
            END) P8,
        SUM(CASE
              WHEN SkuXFcst.StartDate BETWEEN  to_date('2018-12-02','YYYY-MM-DD') + 14 
                                      AND      to_date('2018-12-02','YYYY-MM-DD') + 20 THEN SkuXFcst.Qty
              ELSE 0
            END) P15,
        SUM(CASE
              WHEN SkuXFcst.StartDate BETWEEN  to_date('2018-12-02','YYYY-MM-DD') + 21 
                                      AND      to_date('2018-12-02','YYYY-MM-DD') + 27 THEN SkuXFcst.Qty
              ELSE 0
            END) P22
from    SkuXFcst
GROUP   BY item,
           loc,
           dur

</code>
  </pre>
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