python
from pony.orm import *
db = Database("sqlite", "database.sqlite", create_db=True)
class Author(db.Entity):
name = Required(str)
books = Set("Book")
class Book(db.Entity):
title = Required(str)
author = Required(Author)
db.generate_mapping(create_tables=True)
with db_session:
author = Author.select().first()
author_with_books = select(a for a in Author
if a == author).prefetch(Author.books).first()
print(author_with_books.books)
python
from pony.orm.migrate import schema, migrate
from pony.orm import db_session
db = Database("sqlite", "database.sqlite")
class Person(db.Entity):
name = Required(str)
db.generate_mapping(create_tables=True)
with db_session:
schema = pony.orm.sql.make_schema(db)
migrate(schema)
