I am having a hard time migrating Request Tracker 4.2.8 database from sqlite to mysql.
I've tried the following: http://technolengy.com/articles/rt4-sqlite-woes/
It migrates most of the data, but doesn't migrate Tickets Links (I can't figure out why - i checked and added all the tables) and also it changes the order of some config values in Admin/Tools/System Configuration.
RT has serializer and importer tools that can help when switching databases. The rt-serializer program writes out your database to disk in a format that can be read by the companion rt-importer program. There are many different options because people use these tools for different use cases, so read through them to see what might apply.