Hello, I want to count numbers of combinations. For example, I have following data table in DB2:

ID col1 col2
1 AA aa
1 BB bb
1 CC cc
2 AA aa
2 BB ss
2 CC uu
3 AA aa
3 BB bb
4 AA aaa
4 BB bbb
5 AA aaa
5 BB bbb
5 CC uu

And expected output is:
col1 col2 #combination...