在 SQL Server 中得到错误的结果答案

【问题标题】：Getting wrong result in SQL Server在 SQL Server 中得到错误的结果
【发布时间】：2018-04-01 17:59:50
【问题描述】：

我有两张桌子：

Fee_Payable_to_Students：

f_co |S_Adm_No | apr | may | june | jul | aug | sep | oct | nov | dec | jan | feb | mar
1    |s_1      |  5  | 5   |  5   | 5   |  5  |  5  | 5   |  5  | 5   |  5  | 5   | 5
2    |s_1      |  5  | 5   |  5   | 5   |  5  |  5  | 5   |  5  | 5   |  5  | 5   | 5

Fee_Assign_Waiver_to_Students：

f_co|S_Adm_No | apr | may | june | jul | aug | sep | oct | nov | dec | jan | feb | mar
1   |s_1      |  5  | 5   |  5   | 5   |  5  |  5  | 5   |  5  | 5   |  5  | 5   | 5

我想查看我的结果

S_Adm_No | Installment                                      | Amount  |Payable_Date
s_1      |Quarter-1 (April, May &amp; June)                     |  5      |Apr 15, 2018
s_1      |Quarter-2 (July, August &amp; September)              |  5      |Jul 15, 2018
s_1      |Quarter-3 (October, November &amp; December)          |  5      |Oct 15, 2018
s_1      |Quarter-4 (January, February &amp; March)             |  5      |Jan 15, 2019

我的 SQL 查询在这里：

SELECT 
    unPvt.S_Adm_No, Installment, 
    SUM(Amount) AS Amount, 
    CASE 
       WHEN Installment = 'Quarter-1 (April, May &amp; June)' 
          THEN 'Apr 15, 2018'       
       WHEN Installment = 'Quarter-2 (July, August &amp; September)' 
          THEN 'Jul 15, 2018'       
       WHEN Installment = 'Quarter-3 (October, November &amp; December)' 
          THEN 'Oct 15, 2018'       
       WHEN Installment = 'Quarter-4 (January, February &amp; March)' 
          THEN 'Jan 15, 2019' 
    END AS Payable_Date 
FROM 
    (SELECT 
         pc.S_Adm_No,
         (Apr + May + Jun)-COALESCE(CON.Qa1,0) AS [Quarter-1 (April, May &amp; June)],  
         (Jul + Aug + Sep)-COALESCE(CON.Qa2,0) AS [Quarter-2 (July, August &amp; September)],   
         (Oct + Nov + Dec)-COALESCE(CON.Qa3,0) AS [Quarter-3 (October, November &amp; December)],   
         (Jan + Feb + Mar)-COALESCE(CON.Qa4,0) AS [Quarter-4 (January, February &amp; March)]   
     FROM 
         Fee_Payable_to_Students pc
     LEFT JOIN
         (SELECT 
              S_Adm_no,
              SUM(E_Apr + E_May + E_Jun) Qa1, 
              SUM(E_Jul + E_Aug + E_Sep) Qa2,
              SUM(E_Oct + E_Nov + E_Dec) Qa3, 
              SUM(E_Jan + E_Feb + E_Mar) Qa4
          FROM 
              Fee_Assign_Waiver_to_Students w
          GROUP BY 
              S_Adm_No) AS CON ON pc.S_Adm_no = CON.S_Adm_no
      WHERE
          pc.S_Adm_No = s_1) AS Pvt 
UNPIVOT 
    (Amount FOR Installment IN 
                                ([Quarter-1 (April, May &amp; June)], 
                                [Quarter-2 (July, August &amp; September)], 
                                [Quarter-3 (October, November &amp; December)], 
                                [Quarter-4 (January, February &amp; March)])) AS unPvt 
    GROUP BY unPvt.S_Adm_No,unPvt.Installment

【问题讨论】：

您在此处标记了 4 个不同版本的 SQL Server，其中一个完全不受支持。您真正使用的是哪个？你能适当地更新你的标签吗？
sql-server-2008-r2
如果我不必更正代码以匹配示例数据，作为起点总是更好。

标签： sql-server sql-server-2008 sql-server-2008-r2

【解决方案1】：

我猜你的问题是你有一个多对一的关系，当加入时会产生多对多的关系，所以你所有的分期付款都计算为零。通过对 Fee_Assign_Waiver_to_Students 进行分组，您已经部分解决了该问题，您只需将相同的想法应用于 Fee_Payable_to_Students。为了清楚起见，我会使用 cte 来做这件事。给定

drop table Fee_Payable_to_Students
go
drop table Fee_Assign_Waiver_to_Students
go
create table Fee_Payable_to_Students
(
f_co int,S_Adm_No varchar(10), apr int, may int, jun int, jul int, aug int, sep int, oct int, nov int, dec int, jan int, feb int, mar int
)
go

create table Fee_Assign_Waiver_to_Students
(
f_co int,S_Adm_No varchar(10), apr int, may int, jun int, jul int, aug int, sep int, oct int, nov int, dec int, jan int, feb int, mar int
)
go
insert into Fee_Payable_to_Students values
(1    ,'s_1'      ,  5  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5),
(2    ,'s_1'      ,  5  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5),
(3    ,'s_2'      ,  5  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5),
(4    ,'s_3'      ,  5  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5),
(5    ,'s_3'      ,  5  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5)

insert into Fee_Assign_Waiver_to_Students values
(1   ,'s_1'      ,  null  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5),
(2   ,'s_3'      ,  5  , 5   ,  5   , 5   ,  5  ,  5  , 5   ,  5  , 5   ,  5  , 5   , 5)

这段代码

  ;with cte as( 
        select pc.s_adm_no,
                coalesce(pa1,0) - coalesce(qa1,0) AS [Quarter-1 (April, May &amp; June)],
                coalesce(pa2,0) - coalesce(qa2,0) AS [Quarter-2 (July, August &amp; September)], 
                coalesce(pa3,0) - coalesce(qa3,0) AS [Quarter-3 (October, November &amp; December)],
                coalesce(pa4,0) - coalesce(qa4,0) AS [Quarter-4 (January, February &amp; March)]  
        from
        (
        SELECT 
              p.S_Adm_no,
              SUM(coalesce(Apr,0) + coalesce(May,0) + coalesce(Jun,0)) pa1, 
              SUM(coalesce(Jul,0) + coalesce(Aug,0) + coalesce(Sep,0)) pa2,
              SUM(coalesce(Oct,0) + coalesce(Nov,0) + coalesce(Dec,0)) pa3, 
              SUM(coalesce(Jan,0) + coalesce(Feb,0) + coalesce(Mar,0)) pa4
          FROM 
              Fee_Payable_to_Students p
          GROUP BY 
              S_Adm_No
          ) pc
          left join
         (SELECT 
              S_Adm_no,
              SUM(coalesce(Apr,0) + coalesce(May,0) + coalesce(Jun,0)) Qa1, 
              SUM(coalesce(Jul,0) + coalesce(Aug,0) + coalesce(Sep,0)) Qa2,
              SUM(coalesce(Oct,0) + coalesce(Nov,0) + coalesce(Dec,0)) Qa3, 
              SUM(coalesce(Jan,0) + coalesce(Feb,0) + coalesce(Mar,0)) Qa4
          FROM 
              Fee_Assign_Waiver_to_Students w
          GROUP BY 
              S_Adm_No) AS CON ON pc.S_Adm_no = CON.S_Adm_no
 )
 select unpvt.s_adm_no,unpvt.installment,unpvt.amount,
 CASE 
       WHEN Installment = 'Quarter-1 (April, May &amp; June)' 
          THEN 'Apr 15, 2018'       
       WHEN Installment = 'Quarter-2 (July, August &amp; September)' 
          THEN 'Jul 15, 2018'       
       WHEN Installment = 'Quarter-3 (October, November &amp; December)' 
          THEN 'Oct 15, 2018'       
       WHEN Installment = 'Quarter-4 (January, February &amp; March)' 
          THEN 'Jan 15, 2019' 
 END AS Payable_Date 
  from
 (select * from cte) as pvt 
 unpivot (amount for installment in ([Quarter-1 (April, May &amp; June)], 
                                [Quarter-2 (July, August &amp; September)], 
                                [Quarter-3 (October, November &amp; December)], 
                                [Quarter-4 (January, February &amp; March)])) AS unPvt

结果

s_adm_no   installment                              amount      Payable_Date
---------- ---------------------------------------- ----------- ------------
s_1        Quarter-1 (April, May &amp; June)        20          Apr 15, 2018
s_1        Quarter-2 (July, August &amp; September) 15          Jul 15, 2018
s_1        Quarter-3 (October, November &amp; Decem 15          Oct 15, 2018
s_1        Quarter-4 (January, February &amp; March 15          Jan 15, 2019
s_2        Quarter-1 (April, May &amp; June)        15          Apr 15, 2018
s_2        Quarter-2 (July, August &amp; September) 15          Jul 15, 2018
s_2        Quarter-3 (October, November &amp; Decem 15          Oct 15, 2018
s_2        Quarter-4 (January, February &amp; March 15          Jan 15, 2019
s_3        Quarter-1 (April, May &amp; June)        15          Apr 15, 2018
s_3        Quarter-2 (July, August &amp; September) 15          Jul 15, 2018
s_3        Quarter-3 (October, November &amp; Decem 15          Oct 15, 2018
s_3        Quarter-4 (January, February &amp; March 15          Jan 15, 2019

【讨论】：