How to return multiple values in one column (T-SQL)?
SqlSql ServerSql Server-2005TsqlSql Problem Overview
I have a table UserAliases (UserId, Alias) with multiple aliases per user. I need to query it and return all aliases for a given user, the trick is to return them all in one column.
Example:
UserId/Alias
1/MrX
1/MrY
1/MrA
2/Abc
2/Xyz
I want the query result in the following format:
UserId/Alias
1/ MrX, MrY, MrA
2/ Abc, Xyz
Thank you.
I'm using SQL Server 2005.
p.s. actual T-SQL query would be appreciated :)
Sql Solutions
Solution 1 - Sql
You can use a function with COALESCE.
CREATE FUNCTION [dbo].[GetAliasesById]
(
@userID int
)
RETURNS varchar(max)
AS
BEGIN
declare @output varchar(max)
select @output = COALESCE(@output + ', ', '') + alias
from UserAliases
where userid = @userID
return @output
END
GO
SELECT UserID, dbo.GetAliasesByID(UserID)
FROM UserAliases
GROUP BY UserID
GO
Solution 2 - Sql
Well... I see that an answer was already accepted... but I think you should see another solutions anyway:
/* EXAMPLE */
DECLARE @UserAliases TABLE(UserId INT , Alias VARCHAR(10))
INSERT INTO @UserAliases (UserId,Alias) SELECT 1,'MrX'
UNION ALL SELECT 1,'MrY' UNION ALL SELECT 1,'MrA'
UNION ALL SELECT 2,'Abc' UNION ALL SELECT 2,'Xyz'
/* QUERY */
;WITH tmp AS ( SELECT DISTINCT UserId FROM @UserAliases )
SELECT
LEFT(tmp.UserId, 10) +
'/ ' +
STUFF(
( SELECT ', '+Alias
FROM @UserAliases
WHERE UserId = tmp.UserId
FOR XML PATH('')
)
, 1, 2, ''
) AS [UserId/Alias]
FROM tmp
/* -- OUTPUT
UserId/Alias
1/ MrX, MrY, MrA
2/ Abc, Xyz
*/
Solution 3 - Sql
DECLARE @Str varchar(500)
SELECT @Str=COALESCE(@Str,'') + CAST(ID as varchar(10)) + ','
FROM dbo.fcUser
SELECT @Str
Solution 4 - Sql
group_concat() sounds like what you're looking for.
http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
since you're on mssql, i just googled "group_concat mssql" and found a bunch of hits to recreate group_concat functionality. here's one of the hits i found:
Solution 5 - Sql
You can either loop through the rows with a cursor and append to a field in a temp table, or you could use the COALESCE function to concatenate the fields.
Solution 6 - Sql
Sorry, read the question wrong the first time. You can do something like this:
declare @result varchar(max)
--must "initialize" result for this to work
select @result = ''
select @result = @result + alias
FROM aliases
WHERE username='Bob'