SQL按行号顺序连接字符串

如何解决SQL按行号顺序连接字符串

我使用的是 SQL Server 2014 标准版。

我有以下查询...

SELECT ach.amt,ades.dsline,ades.des
FROM   ##ACHTrans ach
LEFT OUTER JOIN apvodes ades on 1=1 and ades.vo_id = ach.vo_id 
WHERE   ades.voline = '100'
ORDER by ach.apnum,ach.cknum,ach.vo_id,ach.amt desc

这给了我结果...

+------------+---------------+------------------------------+
|   ach.amt  |  ades.dsline  |          ades.des            |
+------------+---------------+------------------------------+
|   1232.50  |             1 | This is the description for  |
|   1232.50  |             2 | The $1,232.50 ACH Amount     |
|    245.18  |             1 | This one is for the $245.18  |
|    245.18  |             2 | transactions details         |
|    245.18  |             3 | that has four lines of info  |
|    245.18  |             4 | in the description.          |
|     79.25  |             1 | This $79.25 item has 1 line. |
|     15.00  |             1 | So does this $15.00 one.     |
+------------+---------------+------------------------------+

我需要一种方法来通过 ach.amt 行获取此信息，并连接 ades.des 信息以获得类似于以下内容的结果：

+------------+--------------------------------------------------------------------------------------------------+
|   Amount   | Description                                                                                      |
+------------+--------------------------------------------------------------------------------------------------+
|   1232.50  | This is the description for The $1,232.50 ACH Amount                                             |
|    245.18  | This one is for the $245.18 transactions details that has four lines of info in the description. |
|     79.25  | This $79.25 item has 1 line.                                                                     |
|     15.00  | So does this $15.00 one.                                                                         |
+------------+--------------------------------------------------------------------------------------------------+

解决方法

这就是 string_agg() 的作用：

select ach.amt,string_agg(des,',') within group (order by dsline)
from t
group by ach.amt;

,

如果没有 STRING_AGG，您将像这样用于 XML PATH：

DECLARE @table TABLE (amt MONEY,dsline INT,[des] VARCHAR(1000));

INSERT @table VALUES
  (1232.50,1,'This is the description for'),(1232.50,2,'The $1,232.50 ACH Amount'),( 245.18,'This one is for the $245.18'),'transactions details'),3,'that has four lines of info'),4,'in the description.'),(  79.25,'This $79.25 item has 1 line.'),(  15.00,'So does this $15.00 one.');

SELECT
  amt,[Description] =
(
  SELECT   t2.[des]+''
  FROM     @table AS t2
  WHERE    t.amt = t2.amt
  ORDER BY t2.dsline
  FOR XML PATH('')
)
--       string_agg(des,') within group (order by dsline)
FROM     @table AS t
GROUP BY amt;

结果：

amt                   Description
--------------------- ---------------------------------------------------------------------------------------------
15.00                 So does this $15.00 one.
79.25                 This $79.25 item has 1 line.
245.18                This one is for the $245.18transactions detailsthat has four lines of infoin the description.
1232.50               This is the description forThe $1,232.50 ACH Amount

,

这可能不是最漂亮的解决方案，但我不得不处理类似的事情，并使用游标将我的字符串连接到临时表中，然后在我的最终连接语句中使用它回到原始表。我使用了表变量，所以你可以自己玩。

以下是您可以使用的代码示例：

declare @tableAmt table (
IDNum int,Amt Money
)

declare @tableDesc table (
IDNum int,LineNum int,Info varchar(10)
)

set nocount on

insert @tableAmt (IDNum,Amt)
values (1,100.00),(2,125.00)

insert @tableDesc (IDNum,LineNum,Info)
values (1,'some text'),(1,'more text'),'different'),'text'),'final')

declare @description table 
   (IDNum int,ConcatDesc varchar(30)
    )


declare @id int,@oldid int,@string char(10),@finalstring varchar(30)

    declare getdata_cursor cursor for
        select IDNum,Info 
        from @tableDesc 
        order by IDNum,LineNum

        open getdata_cursor

        fetch next from getdata_cursor into
        @id,@string
    
        while @@FETCH_STATUS=0
        begin
            
            if @oldid <> @id
                begin 
                    insert @description(IDNum,ConcatDesc)
                    values(@oldid,@finalstring)
                    select @finalstring = ''
                end
        
            select @finalstring = isnull(@finalstring,'') + rtrim(@string) + ' '
        



        select @string = '',@oldid = @id 
    
            fetch next from getdata_cursor into
            @id,@string

        

        end

        insert @description(IDNum,@finalstring)

    close getdata_cursor
    deallocate getdata_cursor


    select ta.IDNum,Amt,ConcatDesc from @tableAmt ta join @description d
    on  ta.IDNum = d.IDNum