sqlalchemy-things’s documentation

Utility collection for development with SQLAlchemy 1.4 / 2.0 ORM.

Installation

Installing sqlalchemy-things with pip:

pip install sqlalchemy-things

Optional requirements

For PostgreSQL support, you also need install asyncpg:

pip install asyncpg

For MySQL support, you also need install aiomysql:

pip install aiomysql

For SQLite3 support, you also need install aiosqlite:

pip install aiosqlite

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'}
    field = sa.Column(sa.String(255))


class ChildB(Parent):
    __tablename__ = 'cascade_pk_child_table_b'
    __mapper_args__ = {'polymorphic_identity': 'child_b'}
    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'}
    field = sa.Column(sa.String(255))


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

Reference

Custom column types

class sqlalchemy_things.column_types.UUIDType(*args, **kwargs)

Bases: sqlalchemy.sql.type_api.TypeDecorator

Backend-agnostic UUID type.

Mixins for signle and joined inheritance

class sqlalchemy_things.declarative.PolymorphicMixin

Bases: sqlalchemy_things.declarative.base.DeclarativeMixin

Polymorphic mixin for single table and joined table inheritance.

Primary key mixins for signle and joined table inheritance

class sqlalchemy_things.declarative.BigIntegerPrimaryKeyMixin

Bases: sqlalchemy_things.declarative.base.DeclarativeMixin

Big integer primary key mixin.

Warning

SQLite backend not support autoincrement for BigInteger column type.

class sqlalchemy_things.declarative.DateTimePrimaryKeyMixin

Bases: sqlalchemy_things.declarative.base.DeclarativeMixin

Datetime primary key mixin.

class sqlalchemy_things.declarative.IntegerPrimaryKeyMixin

Bases: sqlalchemy_things.declarative.base.DeclarativeMixin

Integer primary key mixin.

class sqlalchemy_things.declarative.UUIDPrimaryKeyMixin

Bases: sqlalchemy_things.declarative.base.DeclarativeMixin

UUID primary key mixin.