sqlalchemy-things

Utility collection for development with SQLAlchemy 2.0 ORM.

Documentation

https://sqlalchemy-things.readthedocs.io

Installation

Installing sqlalchemy-things with pip:

pip install sqlalchemy-things

Examples

Single table inheritance

from sqlalchemy import orm
from sqlalchemy_things.declarative import (
    IntegerPrimaryKeyMixin,
    PolymorphicMixin,
)

class Base(orm.DeclarativeBase): ...


class ParentA(Base, IntegerPrimaryKeyMixin, PolymorphicMixin):
    __tablename__ = "single_table"


class ChildA1(ParentA):
    __mapper_args__ = {"polymorphic_identity": "child_a1"}
    some_field = sa.Column(sa.String(255))


class ChildA2(ParentA):
    __mapper_args__ = {"polymorphic_identity": "child_a2"}
    other_filed = sa.Column(sa.String(127))

Joined table inheritance with cascade primary key mixins

from sqlalchemy import orm
from sqlalchemy_things.declarative import (
    CascadeIntegerPrimaryKeyMixin,
    PolymorphicMixin,
)

class Base(orm.DeclarativeBase): ...


class ParentB(Base, CascadeIntegerPrimaryKeyMixin, PolymorphicMixin):
    __tablename__ = "parent_b"


class ChildB1(ParentB):
    __tablename__ = "child_b1"
    __mapper_args__ = {"polymorphic_identity": "child_b1"}
    some_field = sa.Column(sa.String(255))


class ChildB2(ParentB):
    __tablename__ = "child_b2"
    __mapper_args__ = {"polymorphic_identity": "child_b2"}
    some_field = sa.Column(sa.String(127))

Joined table inheritance with simple primary key mixins

from sqlalchemy import orm
from sqlalchemy_things.declarative import (
    IntegerPrimaryKeyMixin,
    ParentPrimaryKeyMixin,
    PolymorphicMixin,
)

class Base(orm.DeclarativeBase): ...


class ParentC(Base, IntegerPrimaryKeyMixin, PolymorphicMixin):
    __tablename__ = "parent_c"


class ChildC1(ParentPrimaryKeyMixin, ParentC):
    __tablename__ = "child_c1"
    __mapper_args__ = {"polymorphic_identity": "child_c1"}
    some_field = sa.Column(sa.String(255))


class ChildC2(ParentPrimaryKeyMixin, ParentC):
    __tablename__ = "child_c2"
    __mapper_args__ = {"polymorphic_identity": "child_c2"}
    some_field = sa.Column(sa.String(127))