ORM Adapters

An adapter connects a specific ORM to CRUDCollection. It handles schema generation and executes database queries.

SQLModel

from fastapi_crud_generator.orm.sqlmodel import SQLModelAdapter

adapter = SQLModelAdapter(
    model=Article,
    get_session=get_session,  # async generator → AsyncSession
)

get_session is an async generator that yields a sqlmodel.ext.asyncio.session.AsyncSession. Standard FastAPI pattern:

from collections.abc import AsyncGenerator
from sqlmodel.ext.asyncio.session import AsyncSession

async def get_session() -> AsyncGenerator[AsyncSession, None]:
    async with AsyncSession(engine) as session:
        yield session

SQLAlchemy (DeclarativeBase)

Works directly with DeclarativeBase models, without SQLModel.

from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
from fastapi_crud_generator.orm.sqlalchemy import SQLAlchemyAdapter

class Base(DeclarativeBase):
    pass

class Article(Base):
    __tablename__ = "article"
    id: Mapped[int] = mapped_column(primary_key=True)
    title: Mapped[str]
    content: Mapped[str]
    published: Mapped[bool] = mapped_column(default=False)

adapter = SQLAlchemyAdapter(
    model=Article,
    get_session=get_session,  # async generator → AsyncSession
)

get_session yields a sqlalchemy.ext.asyncio.AsyncSession.

Tortoise ORM

Tortoise manages connections globally, so no get_session is needed.

from tortoise import fields
from tortoise.models import Model
from fastapi_crud_generator.orm.tortoise import TortoiseAdapter

class Article(Model):
    id = fields.IntField(primary_key=True)
    title = fields.CharField(max_length=200)
    content = fields.TextField()
    published = fields.BooleanField(default=False)

    class Meta:
        table = "article"

adapter = TortoiseAdapter(model=Article)

Initialize Tortoise at application startup via lifespan:

from contextlib import asynccontextmanager
from tortoise import Tortoise

@asynccontextmanager
async def lifespan(app):
    await Tortoise.init(
        db_url="sqlite://:memory:",
        modules={"models": ["myapp.models"]},
    )
    await Tortoise.generate_schemas()
    yield
    await Tortoise.close_connections()

app = FastAPI(lifespan=lifespan)

Comparison

	SQLModel	SQLAlchemy	Tortoise
Requires get_session	yes	yes	no
Composite PK support	yes	yes	no (Tortoise limitation)
crud_config on model	yes	no	no
Schemas built from	model_fields	mapped_column	pydantic_model_creator