ODS query

Hi I have this following requirement :

I have a ODS with following data

Field1 Field2 date

x x1 5292008

x x1 5292008

x x2 5292008

y y1 5292008

y y1 5292008

My report is designed like below

field1 field2 cal/month

x x1 may2008

x x2 may 2008

y y1 may2008

now for the above report I want to add a column Field3. Field3 displays count of each unique field2 value/per month. the report should look like below

field1 field2 cal/month field3

x x1 may2008 2

x x2 may 2008 1

y y1 may2008 2

can you suggest me a way to count total occurence of a field/month in the ODS and display that in the query. Is it possible at Query level??