SQL syntax question

Not sure if this is the right list to post this to or not -- I'm having a problem with getting a MySQL query to work. I need to do two things: (1) multiply the value of x*y (and thus have to do a group by) from fields in one table, AND (2) do a lookup of the name value in another table for a foreign key from the first table. E.g. select sum (qty1*unitprice1), field1, field2 from table1 group by field1, field2 That part works fine, but when I try to mix in the second table, it breaks: select sum (table1.qty1*table1.unitprice1), table1.field1, table1.field2, table2.name from table1, table2 where table1.nameid = table2.id group by table1.field1, table1.field2, table2.name Clearly, you can't group by a foreign table - but then how to do the join to get the name definition from table2? Anne