I've been using the Geonames database for a while now and I must say it is a fantastic invaluable service. However I am having a problem with Brazil. When I import the dump into my database I can match all the locations to their first-order administrative divisions easily enough, however I can not match the locations to the admin2 codes. Most of the locations in Brazil have the admin2 code empty. Am I missing something or am I reading it the wrong way?
I really appreciate and help/comments people may have on this,
Thank you for your reply. I was afraid you would say that the information was missing. I would like to help with finding this data, what exactly is the best method for using border polygons? I am proficient with SQL Server, VB.NET etc.