If it is SQL Server, you can do this using
XML PATH.
You have to query something like-
SELECT Column1
,STUFF((SELECT ', ' + Column2 [text()]
FROM YourTable
WHERE Column1 = t.Column1
FOR XML PATH(''), TYPE)
.value('.','NVARCHAR(MAX)'),1,2,' ') Column2
FROM YourTable t
GROUP BY Column1
EXAMPLE:
DECLARE @MyTable TABLE(Column1 VARCHAR(20), Column2 VARCHAR(20))
INSERT INTO @MyTable VALUES ('Animal', 'dog'),('Animal', 'lion'),('Animal', 'tiger'),('Animal', 'goat')
SELECT Column1
,STUFF((SELECT ', ' + Column2 [text()]
FROM @MyTable
WHERE Column1 = t.Column1
FOR XML PATH(''), TYPE)
.value('.','NVARCHAR(MAX)'),1,2,' ') Column2
FROM @MyTable t
GROUP BY Column1
Hope, it helps :)