SQL在表中显示重复值

Question

我需要获得一个查询，该查询将显示错误捕获的具有相同银行详细信息的人员的详细信息。

然后我需要显示正确的细节以及这些人的错误细节。例如：

1stName   1stAccNo   1stItemSold    2ndName   2ndAccNo  2ndItemSold
Albert    2231432     Item1         John      2231432   Item3
Robert    6321009     Item11        Peter     6321009   Item3

名称和AccNo在一个表上，而ItemSold在另一个表上。

我有以下查询：

select p1.Name As 1stName, p1.AccNo AS 1stAccNo, I.ItemSold AS 1stItemSold, p2.Name AS 2ndName, p2.AccNo AS 2ndAccNo, I.ItemSold As 2ndItemSold
FROM Persons p1 JOIN Persons p2 ON p1.AccNo = p2.AccNo 
INNER JOIN Items I on p.ItemID = I.ItemID

问题是第二个ItemSold不正确，因为它与1stItemSold相同。如何更改查询以便我可以获得正确的结果？

Answer 1

您应该将项目作为第二个表格加入。此外，如果您需要不同的人，则必须包含where p1.id<>p2.id，其中ID是PERSONS表中的主键

select 
p1.Name As 1stName, p1.AccNo AS 1stAccNo, I1.ItemSold AS 1stItemSold, 
p2.Name AS 2ndName, p2.AccNo AS 2ndAccNo, I2.ItemSold As 2ndItemSold
FROM Persons p1 JOIN Persons p2 ON p1.AccNo = p2.AccNo 
INNER JOIN Items I1 on p1.ItemID = I1.ItemID
INNER JOIN Items I2 on p2.ItemID = I2.ItemID
where p1.id<>p2.id

PS：基于评论。返回最后一个ItemSold以避免重复：

select 
p1.Name As 1stName, p1.AccNo AS 1stAccNo, I1.ItemSold AS 1stItemSold, 
p2.Name AS 2ndName, p2.AccNo AS 2ndAccNo, I2.ItemSold As 2ndItemSold
FROM Persons p1 JOIN Persons p2 ON p1.AccNo = p2.AccNo 
left JOIN 
   (select ItemID,ItemSold, 
           row_number() over (PARTITION BY ItemID order by DATE_SOLD DESC) as rn 
    from Items) I1 
         on (p1.ItemID = I1.ItemID) and (rn=1)
left JOIN 
   (select ItemID,ItemSold, 
           row_number() over (PARTITION BY ItemID order by DATE_SOLD DESC) as rn 
    from Items) I2 
         on (p2.ItemID = I2.ItemID) and (rn=1)

where p1.id<>p2.id

Answer 2

我可能会误解您的要求，但听起来您可以使用UNPIVOT/PIVOT功能来获得所需的结果。

如果您知道要转换的列数，则可以对其静态版本进行硬编码。

select *
from
(
  select AccNo,
    val,
    col + cast(rn as varchar(10)) Col_Name
  from
  (
    select p1.accno,
      p1.name,
      p1.itemid,
      i1.id,
      i1.i_name,
      row_number() over(partition by accno order by name) rn
    from persons p1
    left join items i1
      on p1.itemid = i1.id
  ) x
  unpivot
  (
    val
    for col in (name, i_name)
  ) u
) x1
pivot
(
  max(val)
  for col_name in ([name1], [i_name1], [name2], [i_name2])
) p

请参阅SQL Fiddle with Demo

但听起来您将有一些未知数量的项目要转换为列，因此您可以使用动态SQL并创建一个动态版本：

DECLARE @colsUnPivot AS NVARCHAR(MAX),
    @colsPivot AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

SET @colsUnPivot = stuff((select ','+C.name
         from sys.columns as C
         where (C.object_id = object_id('persons') 
                  or C.object_id = object_id('items'))
            and C.name like '%name%'
         for xml path('')), 1, 1, '')

select @colsPivot = STUFF((SELECT  ',' 
                      + quotename(c.name 
                         + cast(p.rn as varchar(10)))
                    from
                    (
                      select row_number() over(partition by accno order by name) rn
                      from persons
                    ) p
                     cross apply 
                      sys.columns as C
                   where (C.object_id = object_id('persons') 
                            or C.object_id = object_id('items'))
                      and C.name like '%name%'
                   group by c.name, p.rn
                   order by p.rn, c.name desc
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query 
  = 'select *
      from
      (
          select AccNo,
            val,
            col + cast(rn as varchar(10)) Col_Name
        from 
        (
          select p1.accno,
            p1.name,
            p1.itemid,
            i1.id,
            i1.i_name,
            row_number() over(partition by accno order by name) rn
          from persons p1
          left join items i1
            on p1.itemid = i1.id
        ) x
        unpivot
        (
          val
          for col in ('+ @colsunpivot +')
        ) u
      ) x1
      pivot
      (
        max(val)
        for col_name in ('+ @colsPivot + ')
      )p'

exec(@query)

请参阅SQL Fiddle with Demo