Click the name of the database to download its JDBC Driver. Let me know if you experience any issues with these JDBC Drivers or if you find a databae/JDBC Driver combination that works for you.

Database Comments/Notes
MySQL Version 5.0 has been used, and therefore tested, extensively.
PostgreSQL Choose the appropriate driver from the table.
Oracle Driver support for Oracle 8i through 11g.
DB2 You'll need an IBM account to download the DB2 JDBC Driver.
SQL Server I've never connected to SQL Server via JDBC, so, good luck!
Firebird Class 4 JDBC Driver that should work without issue.