When you use the standard version of Ruby getting SQLite support is easy, you just install the sqlite3-ruby gem (gem install sqlite3-ruby) and you’re done (you need to have the SQLite libraries and dev headers installed on your system already of course). This does not work for JRuby because the sqlite3-ruby is a native gem (containing C code with extensions on standard Ruby).

So how do you get SQLite to work with JRuby and Rails? Get the gems for JRuby! Assuming that you have SQLite installed on your system, you simply need to install the activerecord-jdbcsqlite3-adapter gem (this will automatically try to install the activerecord-jdbc-adapter and jdbc-sqlite3 gems if you don’t already have them). In your Rails project edit config/database.yml and change the adapter type to jdbcsqlite3 and you’re done

There are a number of activerecord-jdbc gems available (just type “gem search –remote activerecord-jdbc” in your shell to see them), including connectors for Apache Derby, MySQL and PostgreSQL.