I have a table of zip codes (about 42k of them) and a table of offices (500 or so) we work with. I want to, through a lat/lon calculation, update a field called 'closest office' in the zip code table so that I can identify the closest office for each zip. I have the lat/lon calculation, but I don't know how to do the joins to get the query to calcuate the distance for all the offices and return the office with the minimum distance. No matter how I try to join the zips in the two tables, it only returns the matches.