sqlalchemy-things 0.4.0

Utility collection for development with SQLalchemy ORM.

Utility collection for development with SQLAlchemy 1.4 / 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_things.declarative import (
    IntegerPrimaryKeyMixin,
    PolymorphicMixin,
)

metadata = sa.MetaData()
Base = orm.declarative_base(metadata=metadata)


class Parent(Base, IntegerPrimaryKeyMixin, PolymorphicMixin):
    __tablename__ = 'single_table'


class ChildA(Parent):
    __mapper_args__ = {'polymorphic_identity': 'child_a'}
    some_field = sa.Column(sa.String(255))


class ChildB(Parent):
    __mapper_args__ = {'polymorphic_identity': 'child_b'}
    other_filed = sa.Column(sa.String(127))

Joined table inheritance with cascade primary key mixins

from sqlalchemy_things.declarative import (
    CascadeIntegerPrimaryKeyMixin,
    PolymorphicMixin,
)

metadata = sa.MetaData()
Base = orm.declarative_base(metadata=metadata)


class Parent(Base, CascadeIntegerPrimaryKeyMixin, PolymorphicMixin):
    __tablename__ = 'cascade_pk_parent_table'


class ChildA(Parent):
    __tablename__ = 'cascade_pk_child_table_a'
    __mapper_args__ = {'polymorphic_identity': 'child_a'}
    some_field = sa.Column(sa.String(255))


class ChildB(Parent):
    __tablename__ = 'cascade_pk_child_table_b'
    __mapper_args__ = {'polymorphic_identity': 'child_b'}
    some_field = sa.Column(sa.String(127))

Joined table inheritance with simple primary key mixins

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

metadata = sa.MetaData()
Base = orm.declarative_base(metadata=metadata)


class Parent(Base, IntegerPrimaryKeyMixin, PolymorphicMixin):
    __tablename__ = 'inherited_pk_parent_table'


class ChildA(ParentPrimaryKeyMixin, Parent):
    __tablename__ = 'inherited_pk_child_table_a'
    __mapper_args__ = {'polymorphic_identity': 'child_a'}
    some_field = sa.Column(sa.String(255))


class ChildB(ParentPrimaryKeyMixin, Parent):
    __tablename__ = 'inherited_pk_child_table_b'
    __mapper_args__ = {'polymorphic_identity': 'child_b'}
    some_field = sa.Column(sa.String(127))