I want to merge 2 data set. one is a subset of bigger one. I want to choose some more rows from the bigger one whose have same value in 2 column of smaller one.
I want to get rows in df2 whose have the same value in SAMPNO and PERNO
smaller one df1
> SAMPN PERNO other.column
> 1 2 10
> 1 3 9
> 2 2 8
> 2 4 7
bigger one df2
SAMPN PERNO other.column
> 1 2 10
> 1 2 7
> 1 2 9
> 1 3 7
> 1 3 9
> 1 4 7
> 1 5 5
> 1 6 9
> 2 2 9
> 2 2 8
> 2 4 3
> 2 3 1
> 3 3 0
output
> SAMPN PERNO other.column
> 1 2 10
> 1 2 7
> 1 2 9
> 1 3 9
> 1 3 7
> 2 2 8
> 2 2 9
> 2 4 7
> 2 4 3