T-SQL导致列

Question

我有一张表（t1），如下所示

Id  Name    RelId
1   a   2
2   b   3
3   c   4
4   d   3
5   e   6

另一张表（t2）

Id  data    FK  Order
1   aa  2   2
2   bb  2   3
3   cc  2   1
4   dd  2   4
5   ee  2   5
6   ff  3   3
7   gg  3   2
8   hh  3   1
9   ii  4   7
10  jj  4   4
11  kk  4   1
12  ll  4   3
13  mm  6   1
14  nn  6   2
15  oo  6   3
16  pp  6   4

我正在寻找的输出结果是

+----+------+-------+-------+------+----------+
| id | name | RelId | Col 1 | Col2 | Col-Oth  |
+----+------+-------+-------+------+----------+
|  1 | a    |     2 | cc    | aa   | bb,dd,ee |
|  2 | b    |     3 | hh    | gg   | ff       |
|  3 | c    |     4 | kk    | ll   | jj,ii    |
|  4 | d    |     3 | hh    | gg   | ff       |
|  5 | e    |     6 | mm    | nn   | oo,pp    |
+----+------+-------+-------+------+----------+

基于T1表中的Relid与T2中的FK列连接，并使用最少订单数据填充 col1 ， col2 与下一个更高阶数据和 col-oth ，其余数据以逗号分隔排序。

需要你的帮助。

SELECT id,name,RelId, (select data,rownumber() (partition by data order by order asc) from t2 inner join t1 on t1.relid= t2.FK) from t1

Answer 1

尝试以下查询：

DECLARE @TEMP TABLE
(
    Id INT,
    Name VARCHAR(10),
    RelId INT
)

INSERT INTO @TEMP VALUES (1,'a',2),(2,'b',3),(3,'c',4),(4,'d',3),(5,'e',6)

DECLARE @TEMP1 TABLE
(
    Id INT,
    Data varchar(10),
    FK INT,
    [order] INT
)

INSERT INTO @TEMP1 VALUES 
(1 ,'aa',2,2),(2 ,'bb',2,3),(3 ,'cc',2,1),(4 ,'dd',2,4),(5 ,'ee',2,5),
(6 ,'ff',3,3),(7 ,'gg',3,2),(8 ,'hh',3,1),(9 ,'ii',4,7),(10,'jj',4,4),
(11,'kk',4,1),(12,'ll',4,3),(13,'mm',6,1),(14,'nn',6,2),(15,'oo',6,3),(16,'pp',6,4)


SELECT 
    t1.*,
    (SELECT Data FROM (SELECT ROW_NUMBER() OVER(ORDER BY t2.[order]) As RowNo,Data FROM @TEMP1 t2 WHERE t2.FK = t1.RelId)t3 WHERE t3.RowNo=1),
    (SELECT Data FROM (SELECT ROW_NUMBER() OVER(ORDER BY t2.[order]) As RowNo,Data FROM @TEMP1 t2 WHERE t2.FK = t1.RelId)t3 WHERE t3.RowNo=2),
    STUFF((SELECT DISTINCT ',' + Data FROM (SELECT ROW_NUMBER() OVER(ORDER BY t2.[order]) As RowNo,Data FROM @TEMP1 t2 WHERE t2.FK = t1.RelId)t3 WHERE t3.RowNo > 2 FOR XML PATH ('')), 1, 1, '')
FROM
    @TEMP t1

Answer 2

使用PIVOT：

DECLARE @t1 TABLE
    (
      ID INT ,
      Name CHAR(1) ,
      RelID INT
    )
DECLARE @t2 TABLE
    (
      ID INT ,
      Data CHAR(2) ,
      RelID INT ,
      Ordering INT
    )

INSERT  INTO @t1
VALUES  ( 1, 'a', 2 ),
        ( 2, 'b', 3 ),
        ( 3, 'c', 4 ),
        ( 4, 'd', 3 ),
        ( 5, 'e', 6 )

INSERT  INTO @t2
VALUES  ( 1, 'aa', 2, 2 ),
        ( 2, 'bb', 2, 3 ),
        ( 3, 'cc', 2, 1 ),
        ( 4, 'dd', 2, 4 ),
        ( 5, 'ee', 2, 5 ),
        ( 6, 'ff', 3, 3 ),
        ( 7, 'gg', 3, 2 ),
        ( 8, 'hh', 3, 1 ),
        ( 9, 'ii', 4, 7 ),
        ( 10, 'jj', 4, 4 ),
        ( 11, 'kk', 4, 1 ),
        ( 12, 'll', 4, 3 ),
        ( 13, 'mm', 6, 1 ),
        ( 14, 'nn', 6, 2 ),
        ( 15, 'oo', 6, 3 ),
        ( 16, 'pp', 6, 4 );
WITH    cte1
          AS ( SELECT   t1.ID ,
                        t1.Name ,
                        t1.RelID ,
                        t2.Data ,
                        ROW_NUMBER() OVER ( PARTITION BY t1.ID ORDER BY t2.Ordering ) AS rn
               FROM     @t1 t1
                        JOIN @t2 t2 ON t1.RelID = t2.RelID
             ),
        cte2
          AS ( SELECT   ID ,
                        Name ,
                        RelID ,
                        Data ,
                        rn ,
                        STUFF(( SELECT  ',' + Data
                                FROM    cte1 ci
                                WHERE   co.ID = ci.ID
                                        AND rn > 2
                              FOR
                                XML PATH('')
                              ), 1, 1, '') AS Col3
               FROM     cte1 co
             )
    SELECT  ID ,
            Name ,
            RelID ,
            [1] AS Col1 ,
            [2] AS Col2 ,
            Col3
    FROM    cte2 PIVOT( MAX(data) FOR rn IN ( [1], [2] ) ) p

输出：

ID  Name    RelID   Col1    Col2    Col3
1   a       2       cc      aa      bb,dd,ee
2   b       3       hh      gg      ff
3   c       4       kk      ll      jj,ii
4   d       3       hh      gg      ff
5   e       6       mm      nn      oo,pp

我的陈述的执行计划

接受声明的执行计划：

哪个更好？ ：）