db_migrate.py

# coding=utf-8

import imp
from migrate.versioning import api
from app import db
from app.config import SQLALCHEMY_DATABASE_URI
from app.config import SQLALCHEMY_MIGRATE_REPO

if __name__ == '__main__':
    v = api.db_version(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)
    migration = SQLALCHEMY_MIGRATE_REPO + ('/versions/%03d_migration.py' % (v+1))
    tmp_module = imp.new_module('old_model')
    old_model = api.create_model(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)
    exec(old_model, tmp_module.__dict__)
    script = api.make_update_script_for_model(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO, tmp_module.meta, db.metadata)
    open(migration, "wt").write(script)
    api.upgrade(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)
    v = api.db_version(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)
    print('New migration saved as ' + migration)
    print('Current database version: ' + str(v))