Three basic things you will need to know. First, how to connect to the remote database. Many allow an ODBC connection, but different software uses slightly different protocols and, of course, security measures. Second, although SQL is supposed to be "standard", each program has a slightly different dialect. So, as you run queries, you need to be aware of the particular dialect used by the software. For routine SELECT type statements, it may not make much difference. Third, you will, of course, need to know the specific structure of the databases you are accessing - the tables and fields.