data-module

# DataModule - Database Access

DataModule provides async SQLAlchemy integration with connection pooling and REQUEST-scoped sessions.

## Quick Start

```python
from myfy.core import Application
from myfy.data import DataModule, AsyncSession
from myfy.web import route

app = Application()
app.add_module(DataModule())

@route.get("/users/{user_id}")
async def get_user(user_id: int, session: AsyncSession) -> dict:
    # session is auto-injected (REQUEST scope)
    result = await session.execute(select(User).where(User.id == user_id))
    return {"user": result.scalar_one_or_none()}
```

## Configuration

Environment variables use the `MYFY_DATA_` prefix:

| Variable | Default | Description |
|----------|---------|-------------|
| `MYFY_DATA_DATABASE_URL` | `sqlite+aiosqlite:///./myfy.db` | Database connection URL |
| `MYFY_DATA_POOL_SIZE` | `5` | Number of connections in pool |
| `MYFY_DATA_MAX_OVERFLOW` | `10` | Extra connections beyond pool_size |
| `MYFY_DATA_POOL_TIMEOUT` | `30.0` | Seconds to wait for connection |
| `MYFY_DATA_POOL_RECYCLE` | `3600` | Seconds before connection recycled |
| `MYFY_DATA_POOL_PRE_PING` | `True` | Test connections before use |
| `MYFY_DATA_ECHO` | `False` | Log all SQL statements |
| `MYFY_DATA_ENVIRONMENT` | `development` | Environment (blocks auto_create in production) |

## Supported Databases

```python
# SQLite (development)
MYFY_DATA_DATABASE_URL="sqlite+aiosqlite:///./app.db"

# PostgreSQL (production)
MYFY_DATA_DATABASE_URL="postgresql+asyncpg://user:pass@localhost/db"

# MySQL
MYFY_DATA_DATABASE_URL="mysql+aiomysql://user:pass@localhost/db"
```

## Defining Models

```python
from sqlalchemy import String
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column

class Base(DeclarativeBase):
    pass

class User(Base):
    __tablename__ = "users"

    id: Mapped[int] = mapped_column(primary_key=True)
    email: Mapped[str] = mapped_column(String(255), unique=True)
    name: Mapped[str] = mapped_column(String(100))
```