Concatenate values based on ID

Solution 1:

You can not be sure about the order of the strings concatenated without an order by statement in the sub query. The .value('.', 'varchar(max)') part is there to handle the case where Label contains XML-unfriendly characters like &.

declare @T table(Response_ID int, Label varchar(50))
insert into @T values
(12147,          'It was not clear'),
(12458,          'Did not Undersstand'),
(12458,          'Was not resolved'),
(12458,          'Did not communicate'),
(12586,          'Spoke too fast'),
(12587,          'Too slow')

select T1.Response_ID,
       stuff((select ','+T2.Label
              from @T as T2
              where T1.Response_ID = T2.Response_ID
              for xml path(''), type).value('.', 'varchar(max)'), 1, 1, '') as Label
from @T as T1
group by T1.Response_ID

Solution 2:

Check the link below, it approaches your problem with many different solutions

http://www.simple-talk.com/sql/t-sql-programming/concatenating-row-values-in-transact-sql/

Solution 3:

Given this sample data:

CREATE TABLE #Results(Response_ID int, Label varchar(80));

INSERT #Results(Response_ID, Label) VALUES
  (12147, 'It was not clear'),
  (12458, 'Did not Undersstand'),
  (12458, 'Was not resolved'),
  (12458, 'Did not communicate'),
  (12586, 'Spoke too fast'),
  (12587, 'Too slow');

On older versions you can use FOR XML PATH for (grouped) string aggregation:

SELECT r.Response_ID, Label = STUFF((SELECT ',' + Label
    FROM #Results WHERE Response_ID = r.Response_ID
    FOR XML PATH(''), TYPE).value(N'./text()[1]', N'varchar(max)'), 1, 1, '')
  FROM #Results AS r
  GROUP BY r.Response_ID;

If you are on SQL Server 2017 or greater, the query is much simpler:

SELECT r.Response_ID, Label = STRING_AGG(Label, ',')
  FROM #Results AS r
  GROUP BY r.Response_ID;