Temporary SQL server for tests

I'm writing a Node.js module that generates MySQL statements, and I want to run it against a test suite.

I want to start up an SQL server (don't mind which, but MySQL seems easiest to set up across all platforms) for the duration of the tests, and then shut it down again.

What is the best way to do this? Is there a neat way that doesn't conflict with a MySQL instance already running on the machine?