Async SQLModel¶

SQLModel supports asynchronous database operations out of the box using SQLAlchemy's async features and the AsyncSession provided by SQLModel.

When to use Async¶

Asynchronous programming is particularly useful for Web APIs (like FastAPI) that handle many concurrent connections and spend much of their time waiting for the database to respond.

Create the Async Engine¶

To use async, you need an async database driver (like aiosqlite for SQLite or asyncpg for PostgreSQL).

from sqlalchemy.ext.asyncio import create_async_engine
from sqlmodel import SQLModel

sqlite_url = "sqlite+aiosqlite:///database.db"
engine = create_async_engine(sqlite_url, echo=True)

async def init_db():
    async with engine.begin() as conn:
        await conn.run_sync(SQLModel.metadata.create_all)

Use AsyncSession¶

Use from sqlmodel.ext.asyncio.session import AsyncSession to perform async operations.

from sqlmodel.ext.asyncio.session import AsyncSession
from sqlmodel import select

async def get_heroes():
    async with AsyncSession(engine) as session:
        statement = select(Hero)
        results = await session.exec(statement)
        return results.all()

Integration with FastAPI¶

In FastAPI, you can use a dependency to provide an AsyncSession:

async def get_session():
    async with AsyncSession(engine) as session:
        yield session