Examples
========
Single table inheritance
------------------------
.. code-block:: python

  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
--------------------------------------------------------
.. code-block:: python

  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
-------------------------------------------------------
.. code-block:: python

  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))