Group different rows in one by combining strings

Question

I have a data set like this:

Column1  Column2
   1       A
   1       B
   1       C
   2       D
   2       E
   2       F
   2       G
   3       H
   3       I         


        

Answer 1

 SELECT Column1, group_concat(Column2) FROM Table GROUP BY Column1

group_concat takes an optional second argument (a string) to use as the concatenation separator if you don't want a single ',' character.