Comment 12 for bug 1184484

That branch is just master + 2 cherry-picked commits.
I had the same problem as yours; it was due to a change in the configuration for the sql connetion section, which was supposed to be backward compatibile but apparently isn't. The sql connection is being ignored and it defaults to an empty sqlite db.

In ovs_quantum_plugin.ini, try and change [DATABASE] section to lowercase, and sql_connection to connection. This worked for me, something like the following:

[database]
connection =mysql://root:password@localhost/ovs_quantum?charset=utf8