Combine the same field of multiple records into a single string

Stuff (SELECT ', ' + fieldname from  tablename FOR XML Path (")), 1, 1, ')

The function of this whole sentence is to concatenate the contents of a multiline FieldName field, separated by commas.
such as tables
FieldName
-----------
Aaa
Bbb
Ccc
After concatenation is the string: AAA,BBB,CCC
The FOR XML path is a way to generate XML that is supported by a later version of SQL Server 2005 . Refer to Books Online for details on how to use them.
The role of the stuff function is to remove the comma delimiter from the front of the string.

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在sql server 2000中只能用函数解决 create table tb(id  int , value  varchar (10))  insert into tb  values (1,  ‘aa‘ )  insert into tb  values (1,  ‘bb‘ )  insert into tb  values (2,  ‘aaa‘ )  insert into tb  values (2,  ‘bbb‘ )  insert into tb  values (2,  ‘ccc‘ )  go  --1. 创建处理函数  CREATE FUNCTION dbo.f_strUnite(@id  int )  RETURNS varchar (8000)  AS BEGIN      DECLARE @str  varchar (8000)       SET @str =  ‘‘      SELECT @str = @str +  ‘,‘ + value  FROM tb  WHERE [email protected]       RETURN STUFF(@str, 1, 1,  ‘‘ )  END GO  -- 调用函数  SELECt id, value = dbo.f_strUnite(id)  FROM tb  GROUP BY id    go   id          value       ----------- -----------  1          aa,bb  2          aaa,bbb,ccc   

Combine the same field of multiple records into a single string