I wanted for a long time to have one database client to access databases of different types like HSQLDB, MySQL, SQLite, etc. I finally found an interesting one in Java. It only needs to have the JDBC driver for the RDBMS that should be accessed. This is a free software tool named SQuirreL SQL (home page).
I also wanted to access SQLite databases throught this client or any
Java code. Finding the JDBC driver for SQLite is quite hard, but here is
a working one. To use it with SQuirreL SQL, simply place the JDBC
jar file in the lib directory of SQuirreL installation and add a new
JDBC driver with the class org.sqlite.JDBC
.