SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db"
# SQLALCHEMY_DATABASE_URL = "postgresql://user:password@postgresserver/db"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

from ..database import Base
from ..main import app, get_db

SQLALCHEMY_DATABASE_URL = "sqlite://"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL,
    connect_args={"check_same_thread": False},
    poolclass=StaticPool,
)
TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


Base.metadata.create_all(bind=engine)


def override_get_db():
    try:

```

#### Note

The argument:

```Python
connect_args={"check_same_thread": False}
```

...is needed only for `SQLite`. It's not needed for other databases.

!!! info "Technical Details"

    By default SQLite will only allow one thread to communicate with it, assuming that each thread would handle an independent request.

```

!!! tip
    ✔️ 🤯 👈 🚥 👆 💚 ⚙️ 🎏 💽, 💖 ✳, 👆 🚫 🚫 🔀 🎻. 👆 🔜 💪 ⚙️ 🎏 🏒 💽 🎓.

#### 🗒

❌:

```Python
check_same_thread=False
```

🌓 1️⃣ 🇸🇲 🔰:

```Python
connect_args={"check_same_thread": False}
```

...⚫️ 💪 🕴 `SQLite`.

!!! info "📡 ℹ"

    ⚫️❔ 🎏 📡 ℹ [🗄 (🔗) 💽](../tutorial/sql-databases.md#_7){.internal-link target=_blank} ✔.

        yield await run_in_threadpool(cm.__enter__)
    except Exception as e:
        ok = bool(
            await anyio.to_thread.run_sync(
                cm.__exit__, type(e), e, None, limiter=exit_limiter
            )
        )
        if not ok:
            raise e
    else:
        await anyio.to_thread.run_sync(
            cm.__exit__, None, None, None, limiter=exit_limiter

    This was useful in older frameworks designed to have one single thread per request, no more, no less.

    Using this, each request would have its own database connection/session, which is the actual final goal.

SQLALCHEMY_DATABASE_URL = "sqlite:///./sql_app.db"
# SQLALCHEMY_DATABASE_URL = "postgresql://user:password@postgresserver/db"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False}
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

### Other utility functions

Any other utility function that you call directly can be created with normal `def` or `async def` and FastAPI won't affect the way you call it.

    sqlalchemy.Column("text", sqlalchemy.String),
    sqlalchemy.Column("completed", sqlalchemy.Boolean),
)


engine = sqlalchemy.create_engine(
    DATABASE_URL, connect_args={"check_same_thread": False}
)
metadata.create_all(engine)


class NoteIn(BaseModel):
    text: str
    completed: bool


class Note(BaseModel):
    id: int
    text: str
    completed: bool

### Andere Hilfsfunktionen