models.py 文件源码

def check_db_schema_version():
    """ Ensure DB schema is correct version. Drop tables if not. """
    db_schema_version = None

    try:
        db_schema_version = Setting.get(Setting.name == 'DB_SCHEMA_VERSION').value
    except (peewee.OperationalError, peewee.DoesNotExist, peewee.ProgrammingError) as e:
        printdbg("[info]: Can't get DB_SCHEMA_VERSION...")

    printdbg("[info]: SCHEMA_VERSION (code) = [%s]" % SCHEMA_VERSION)
    printdbg("[info]: DB_SCHEMA_VERSION = [%s]" % db_schema_version)
    if (SCHEMA_VERSION != db_schema_version):
        printdbg("[info]: Schema version mis-match. Syncing tables.")
        try:
            existing_table_names = db.get_tables()
            existing_models = [m for m in db_models() if m._meta.db_table in existing_table_names]
            if (existing_models):
                printdbg("[info]: Dropping tables...")
                db.drop_tables(existing_models, safe=False, cascade=False)
        except (peewee.InternalError, peewee.OperationalError, peewee.ProgrammingError) as e:
            print("[error] Could not drop tables: %s" % e)