The following should work.

CREATE PROCEDURE [dbo].[Get_Ques_id_for_can](

@candidate_id varchar(max),

@Exam_id varchar(max),

@sec_id bigint,

@Q_id varchar(max) OUTPUT

)

AS

declare @table_query nvarchar(max);

declare @table nvarchar(max);

declare @sparam nvarchar(max);

set @sparam = N'@SecID bigint, @QID varchar(max) OUTPUT';

set @table = @candidate_ID + @Exam_id;

declare @id varchar(50);

declare @ques_id varchar(50);

set @table_query = --N'SELECT @ID = [ID], @QID = [Question_ID] FROM [' + @table + N'] WHERE [Section_ID] = ' + CONVERT(varchar(50),@sec_id)

N'select

@QID = stuff((select

''|'' + cast(ID as varchar) + '';'' + cast(Question_ID as varchar)

from

[' + @table + N']

where

Section_id = @SecID

order by

ID

for xml path(''''),TYPE).value(''.'',''varchar(max)''),1,1,'''')'

exec sp_executesql @table_query, @sparam, @SecID = @sec_id, @QID = @Q_id OUTPUT;

GO

/* how this procedure should be invoked. The ?? represent values passed into the procedure */

declare @QuesID varchar(max);

exec dbo.Get_Ques_id_for_can @candidate_id = ??, @Exam_id = ??, @sec_id = ??, @Q_id = @QuesID OUTPUT;

go