How to make a query with group_concat in sql serve

2018-12-31 01:27发布

This question already has an answer here:

I know that in sql server we cannot use Group_concat function but here is one issue i have in which i need to Group_Concat my query.I google it found some logic but not able to correct it.My sql query is

select  m.maskid,m.maskname,m.schoolid,s.schoolname,
md.maskdetail
from tblmask m join school s on s.id = m.schoolid 
join maskdetails md on m.maskid = md.maskid
order by m.maskname ;

It gives me result like

enter image description here

Just look first 3 rows In that maskid,maskname,schoolid,schoolname is same but maskdetail is different so want to one row for that in which last column can contain all maskdetails as per maskid and so on.

I want my output like

enter image description here

And so on.So please help me while making a query for that.

Thanks in advance.

4条回答
萌妹纸的霸气范
2楼-- · 2018-12-31 01:39

Query:

SELECT
      m.maskid
    , m.maskname
    , m.schoolid
    , s.schoolname
    , maskdetail = STUFF((
          SELECT ',' + md.maskdetail
          FROM dbo.maskdetails md
          WHERE m.maskid = md.maskid
          FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, '')
FROM dbo.tblmask m
JOIN dbo.school s ON s.ID = m.schoolid
ORDER BY m.maskname

Additional information:

String Aggregation in the World of SQL Server

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浅入江南
3楼-- · 2018-12-31 01:41
Select
      A.maskid
    , A.maskname
    , A.schoolid
    , B.schoolname
    , STUFF((
          SELECT ',' + T.maskdetail
          FROM dbo.maskdetails T
          WHERE A.maskid = T.maskid
          FOR XML PATH('')), 1, 1, '') as maskdetail 
FROM dbo.tblmask A
JOIN dbo.school B ON B.ID = A.schoolid
Group by  A.maskid
    , A.maskname
    , A.schoolid
    , B.schoolname
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情到深处是孤独
4楼-- · 2018-12-31 01:44

Please run the below query, it doesn't requires STUFF and GROUP BY in your case:

Select
      A.maskid
    , A.maskname
    , A.schoolid
    , B.schoolname
    , CAST((
          SELECT  T.maskdetail+','
          FROM dbo.maskdetails T
          WHERE A.maskid = T.maskid
          FOR XML PATH(''))as varchar(max)) as maskdetail 
FROM dbo.tblmask A
JOIN dbo.school B ON B.ID = A.schoolid
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旧时光的记忆
5楼-- · 2018-12-31 01:51

This can also be achieved using the Scalar-Valued Function in MSSQL 2008
Declare your function as following,

CREATE FUNCTION [dbo].[FunctionName]
(@MaskId INT)
RETURNS Varchar(500) 
AS
BEGIN

    DECLARE @SchoolName varchar(500)                        

    SELECT @SchoolName =ISNULL(@SchoolName ,'')+ MD.maskdetail +', ' 
    FROM maskdetails MD WITH (NOLOCK)       
    AND MD.MaskId=@MaskId

    RETURN @SchoolName

END

And then your final query will be like

SELECT m.maskid,m.maskname,m.schoolid,s.schoolname,
(SELECT [dbo].[FunctionName](m.maskid)) 'maskdetail'
FROM tblmask m JOIN school s on s.id = m.schoolid 
ORDER BY m.maskname ;

Note: You may have to change the function, as I don't know the complete table structure.

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