SQLModel: Interoperability for SQLAlchemy, Pydantic, and FastAPI

[amotl]

About

SQL databases in Python, designed for simplicity, compatibility, and robustness.

Details

SQLModel is a library for interacting with SQL databases from Python code, with Python objects. It is designed to be intuitive, easy to use, highly compatible, and robust.

It combines SQLAlchemy and Pydantic and tries to simplify the code you write as much as possible, allowing you to reduce the code duplication to a minimum, but while getting the best developer experience possible.

SQLModel is, in fact, a thin layer on top of Pydantic and SQLAlchemy, carefully designed to be compatible with both.

Features

SQLModel is based on Python type annotations, and powered by Pydantic and SQLAlchemy. The key features are:

• Intuitive to write: Great editor support. Completion everywhere. Less time debugging. Designed to be easy to use and learn. Less time reading docs.
• Easy to use: It has sensible defaults and does a lot of work underneath to simplify the code you write.
• Compatible: It is designed to be compatible with FastAPI, Pydantic, and SQLAlchemy.
• Extensible: You have all the power of SQLAlchemy and Pydantic underneath.
• Short: Minimize code duplication. A single type annotation does a lot of work. No need to duplicate models in SQLAlchemy and Pydantic.

Standing on the shoulders of giants

• Application model classes derive from an SQLModel model.

• By doing so, your model class becomes an SQLAlchemy model at the same time. So, you can combine it and use it with other SQLAlchemy models, or you could easily migrate applications with SQLAlchemy to SQLModel.

• At the same time, it also becomes a Pydantic model. You can use inheritance with it to define all your data models while avoiding code duplication. That makes it very easy to use with FastAPI.

Resources

• https://sqlmodel.tiangolo.com/
• https://github.com/fastapi/sqlmodel