獲取最高值或重複值

Question

該合併數據鏈接到我的previous Qn

Table A: 
ID Rank Name 
1 100 Name1 
1 45 Name2 
2 60 Name3 
2 42 Name4 
2 88 Name5 
3 50 name6 
3 50 name7 

Table B: 
ID FileName 
1 fn1 
2 fn2 
3 fn3 

我要的是

1 fn1 name1 
2 fn2 name5 
3 fn3 name6,name7 

這裏是我的代碼，這並不處理duplciate以上的行列，所以我得到兩行的值爲3.

select B.*,A.Name 
LEFT JOIN (SELECT A.Id, MAX(A.Rank)as Rank 
    FROM A 
    GROUP BY A.Id 
    ) AS NewA 
      JOIN A 
       on A.Rank = NewA.Rank 
        AND A.ID = NewA.Id 
    on NewA.ID = B.ID 

如何修改此給我A.name分離用逗號分隔時候的行列是否相同？

感謝

Answer 1

您將需要使用CTE壓平了這一點。

這應該直接插入到SQL中，並使用給出的數據作爲示例。顯然，你將需要更新的查詢爲您真實的數據，因爲這可能是不是你真正的模式

create table #tableA (ID int, [rank] int, name varchar(max)) 
insert into #tableA values(1,100,'Name1') 
insert into #tableA values(1,45,'Name2') 
insert into #tableA values(2,60,'Name3') 
insert into #tableA values(2,42,'Name4') 
insert into #tableA values(2,88,'Name5') 
insert into #tableA values(3,50,'Name6') 
insert into #tableA values(3,50,'Name7') 

create table #tableB (ID int, [FileName] varchar(max)) 
insert into #tableB values(1,'fn1') 
insert into #tableB values(2,'fn2') 
insert into #tableB values(3,'fn3') 

SELECT B.*,A.Name, ROW_NUMBER() OVER (PARTITION BY A.ID ORDER BY A.[rank]) AS RowNum 
INTO #RankedTable 
FROM #tableB as B 
    LEFT JOIN ( 
     SELECT A.Id, MAX(A.Rank)as Rank 
     FROM #tableA AS A 
     GROUP BY A.Id 
     ) AS NewA 
    JOIN #tableA AS A 
     on A.Rank = NewA.Rank 
      AND A.ID = NewA.Id 
    on NewA.ID = B.ID 

;WITH ConcatenationCTE (ID, [FileName], Name, RowNum) 
AS 
(
    SELECT ID, [FileName], Name, RowNum 
    FROM #RankedTable 
    WHERE RowNum = 1 
    UNION ALL 
    SELECT #RankedTable.ID, #RankedTable.[FileName], 
      ConcatenationCTE.Name + ',' + #RankedTable.Name AS Name, 
      #RankedTable.RowNum 
    FROM #RankedTable 
     JOIN ConcatenationCTE 
      ON ConcatenationCTE.ID = #RankedTable.ID 
       AND ConcatenationCTE.RowNum +1 = #RankedTable.RowNum 
) 
SELECT ConcatenationCTE.ID, [FileName], Name 
FROM ConcatenationCTE 
     JOIN 
    (SELECT ID, MAX(RowNum) AS RowNum 
     FROM ConcatenationCTE GROUP BY ID) AS FinalValues 
     ON FinalValues.ID = ConcatenationCTE.ID 
      AND FinalValues.RowNum = ConcatenationCTE.RowNum 

Answer 2

;WITH x AS 
(
    SELECT ID, [Rank], Name, 
     rn = DENSE_RANK() OVER (PARTITION BY ID ORDER BY [Rank] DESC) 
     FROM dbo.TableA 
), y AS 
(
    SELECT x.ID, x.Name, f.[Filename] 
    FROM x INNER JOIN dbo.TableB AS f 
    ON x.ID = f.ID WHERE x.rn = 1 
) 
SELECT DISTINCT ID, [Filename], Names = STUFF((SELECT ',' + name 
    FROM y AS y2 WHERE y.ID = y2.ID 
    FOR XML PATH(''), TYPE).value('.[1]', 'nvarchar(max)'), 1, 1, '') 
FROM y 
ORDER BY ID; 

Answer 3

select B.ID, 
     B.[FileName], 
     stuff((select ',' + A1.name 
       from TableA as A1 
       where B.ID = A1.ID and 
        A1.[Rank] = (select max(A2.[Rank]) 
           from TableA as A2     
           where A1.ID = A2.ID) 
       for xml path(''), type).value('.', 'varchar(max)'), 1, 1, '') as Names 
from TableB as B 

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