Working with multiple databases

Pony can work with several databases simultaneously. In the example below we use PostgreSQL for storing user information and MySQL for storing information about addresses:

db1 = Database()
class User(db1.Entity):
    ...
db1.bind('postgres', ...)
db2 = Database()
class Address(db2.Entity):
    ...
db2.bind('mysql', ...)
@db_session
def do_something(user_id, address_id):
    u = User[user_id]
    a = Address[address_id]
    ...

On exiting from the do_something() function Pony will perform commit() or rollback() to both databases. If you need to commit to one database before exiting from the function you can use db1.commit() or db2.commit() methods.