Models Manager

[ghost]

Feature description::

Create a models manager, this manager will have all the models and it will be here that it will contain several ready-made functions. As the create_tables method that will create tables regardless of having to create one table before another, it will do this automatically. It will also make it easier to create future features.

Need:

from databases import Database
from duck_orm.sql import fields as Field
from duck_orm.model import Model, ManagerModel

db = Database('sqlite:///example.db')
manager = ManagerModel()
await db.connect()

class City(Model):
    __tablename__ = 'cities'
    __db__ = db
    manager = manager

    id: int = Field.Integer(primary_key=True, auto_increment=True)
    name: str = Field.String(unique=True)

    def relationships(self):
        self.persons = OneToMany(
            model=Person,
            name_in_table_fk='city',
            name_relation='person_city'
        )


class Person(Model):
    __tablename__ = 'persons'
    __db__ = db
    manager = manager

    id: int = Field.Integer(primary_key=True, auto_increment=True)
    first_name: str = Field.String(unique=True)
    last_name: str = Field.String(not_null=True)
    age: int = Field.BigInteger()
    salary: int = Field.BigInteger()
    city: City = ForeignKey(model=City, name_in_table_fk='id')

# He will know that he must create the `City` table first.
await manager.create_tables()