Multiple DatabasesΒΆ

Because you can use Flask-SQLAlchemy (using the framework SQLA class) multiple databases is supported.

You can configure them the following way, first setup config.py:

SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(basedir, 'app.db')

SQLALCHEMY_BINDS = {
    'my_sql1': 'mysql://root:password@localhost/quickhowto'
    'my_sql2': 'mysql://root:password@externalserver.domain.com/quickhowto2'
}

The SQLALCHEMY_DATABASE_URI is the default connection this is where the framework’s security tables will be created. The SQLALCHEMY_BINDS are the extra binds.

Now you can configure which models reside on which database using the __bind_key__ property

class Model1(Model):
    __bind_key__ = 'my_sql1'
    id = Column(Integer, primary_key=True)
    name =  Column(String(150), unique = True, nullable=False)


class Model2(Model):
    __bind_key__ = 'my_sql2'
    id = Column(Integer, primary_key=True)
    name =  Column(String(150), unique = True, nullable=False)


class Model3(Model):
    id = Column(Integer, primary_key=True)
    name =  Column(String(150), unique = True, nullable=False)
On this example:
  • Model1 will be on the local MySql instance with db ‘quickhowto’.
  • Model2 will be on the externalserver.domain.com MySql instance with db ‘quickhowto2’.
  • Model3 will be on the default connection using sqlite.