'DB based preference store'

def upgrade_version_12(self):

    script = u'\n                                DROP    TABLE    IF    EXISTS    preferences;\n                                CREATE    TABLE    preferences(id    INTEGER    PRIMARY    KEY,\n                                                                                                                                    key    TEXT    NOT    NULL,\n                                                                                                                                    val    TEXT    NOT    NULL,\n                                                                                                                                    UNIQUE(key));\n                                '
    self.db.execute(script)
