R filtering table and inserting information

Question

I currently have following table structure

Table1

id  a
11  4
11  3
22  1
22  3
22  5
33  2
33  1
44  6
44  8
66  5
66  7
77  6

Table2

id  score 
11  12
33  22
44  20

I want to delete every row from Table1, that does not contain any of the id in Table2$id. unique(Table2$id) should generate such an unique id list. Further, I need to write the score from Table2 into each corresponding id of Table1. The desired dataframe would be:

Result

id  a score 
11  4 12
11  3 12
33  2 22
33  1 22
44  6 20
44  8 20

Answer 1

merge(Table2, Table1, by = "id")

should do it.