In addition to solution 1,
this article[
^] discusses various methods for concatenating row values in SQL. For example:
SELECT
e1.Id,
[Employee Name] = STUFF
(
(
SELECT ', ' + [Employee Name]
FROM YourTable As e2
WHERE e2.Id = e1.Id
ORDER BY [Employee Name]
FOR XML PATH(''), TYPE
).value('.', 'varchar(max)')
, 1, 2, '')
FROM
YourTable As e1
GROUP BY
Id
;