Since you didn't give too much information I thought of a few other interpetations of what you asked.
If field1 is a numeric value you might want the sum of the field grouped by field2
Select field2, sum(field1)
From Table
Group by field2
or you might want to know how many records of field1 there are that are also rouped by field2
Select field2, field1, count(*)
From table
Group by field2, field1
I'm sure one of the 3 syntax's will work for what you are asking.