pydantic-sqlalchemy-type-decorator

Seamlessly use Pydantic 2 models in a Postgres SQLAlchemy model

Installation

The package is available on pypi.

You can install this package using pip:

pip install pydantic_sqlalchemy_deco

Requirements

This library requires:

• Pydantic 2+
• SQLAlchemy (2.0+?)
• Postgres with JSONB support

Other versions may be supported as well, but please open an issue if you run into any problems.

Usage

Given some Pydantic model called MyCustomModel, you can specify your columns like:

from pydantic_sqlalchemy_deco.decorator import PydanticJSON

...

# Define Pydantic model somewhere:
class MyCustomModel(BaseModel):
    custom_id: int = 0


# Define your SQLAlchemy model:
class MyEntry(Base):

    custom_data: Mapped[MyCustomModel] = mapped_column(PydanticJSON(MyCustomModel))

Then, you can use the custom_data column as you'd expect:

entry = MyEntry(
    custom_data=MyCustomModel(custom_id=1234)
)

...

print(entry.custom_data.custom_id)

BaseModel changes

If your BaseModel has custom serializers, you can specify this using the T parameter:

    custom_data: Mapped[MyCustomModel] = mapped_column(PydanticJSON[CoolerBaseModel](MyCustomModel))