mysql 5.6 – Result from Combination of 2 columns

I want results from one table only but in a different manner. I have a combination of data like,(A -> 1) and (B -> 1,2) which we can put in where clause,so result would be only 3 rows i.e. 1,2,3 not 4.suggest me a query for this.

Column 1   Column 2
   A          1
   B          2
   B          1
   A          2