fix: resolve issue for bounty

Author: utkarsh3010-maker

docs/async/tutorial.md

@@ -0,0 +1,68 @@
+# Async Support
+
+SQLModel supports asynchronous operations by leveraging SQLAlchemy's `asyncio` extension.
+
+## Setup
+
+To use async features, you need an async database driver. For SQLite, use `aiosqlite`. For PostgreSQL, use `asyncpg`.
+
+```bash
+pip install aiosqlite
+```
+
+## Async Engine and Session
+
+You can create an async engine using `create_async_engine` and manage sessions with `AsyncSession`.
+
+```python
+from sqlalchemy.ext.asyncio import create_async_engine
+from sqlalchemy.orm import sessionmaker
+from sqlmodel import Field, SQLModel, select
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+class Hero(SQLModel, table=True):
+    id: int | None = Field(default=None, primary_key=True)
+    name: str
+    secret_name: str
+    age: int | None = None
+
+DATABASE_URL = "sqlite+aiosqlite:///database.db"
+engine = create_async_engine(DATABASE_URL, echo=True)
+
+async def init_db():
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.create_all)
+
+async def create_hero():
+    async with AsyncSession(engine) as session:
+        hero = Hero(name="Deadpond", secret_name="Dive-man")
+        session.add(hero)
+        await session.commit()
+        await session.refresh(hero)
+        print(f"Created hero: {hero.name}")
+
+async def select_heroes():
+    async with AsyncSession(engine) as session:
+        statement = select(Hero).where(Hero.name == "Deadpond")
+        results = await session.exec(statement)
+        hero = results.first()
+        print(f"Found hero: {hero.name}")
+
+import asyncio
+
+async def main():
+    await init_db()
+    await create_hero()
+    await select_heroes()
+
+if __name__ == "__main__":
+    asyncio.run(main())
+```
+
+## Key Differences from Sync
+
+1. **Engine**: Use `create_async_engine` instead of `create_engine`.
+2. **Session**: Use `sqlmodel.ext.asyncio.session.AsyncSession` instead of `sqlmodel.Session`.
+3. **Execution**: Use `await session.exec(statement)` instead of `session.exec(statement)`.
+4. **Commit/Refresh**: Use `await session.commit()` and `await session.refresh(instance)`.
+5. **Table Creation**: Use `conn.run_sync(SQLModel.metadata.create_all)` because `create_all` is a synchronous method.