Total Count by categories

Hi All,

I have a table of codes with a count of users and a count of bookings. Something like this:

Code     Users     Bookings

123       25            12

456       50            20

789       100          30

I have another table that matches code to a city. There are 10's of different codes related to each city. I want to summerise users and bookings by city so have created a relationship between the 2 tables. When I look at users and bookings by city, get the same number (the total users and bookings for all cities) for each city. So if 123 and 456 are London and 789 is Cardiff, then the table would look something like:

City          Users   Bookings

London     175       62

Cardiff       175       62

Any help appreciated.

Thanks,