📝 Update SQLAlchemy docs, with current workaround

docs/src/sql_databases/tutorial001.py

@@ -1,7 +1,8 @@
 from fastapi import FastAPI
 from sqlalchemy import Boolean, Column, Integer, String, create_engine
 from sqlalchemy.ext.declarative import declarative_base, declared_attr
-from sqlalchemy.orm import scoped_session, sessionmaker
+from sqlalchemy.orm import sessionmaker
+from starlette.requests import Request
 
 # SQLAlchemy specific code, as with any other app
 SQLALCHEMY_DATABASE_URI = "sqlite:///./test.db"
@@ -10,9 +11,7 @@ SQLALCHEMY_DATABASE_URI = "sqlite:///./test.db"
 engine = create_engine(
     SQLALCHEMY_DATABASE_URI, connect_args={"check_same_thread": False}
 )
-db_session = scoped_session(
-    sessionmaker(autocommit=False, autoflush=False, bind=engine)
-)
+Session = sessionmaker(autocommit=False, autoflush=False, bind=engine)
 
 
 class CustomBase:
@@ -34,12 +33,16 @@ class User(Base):
 
 Base.metadata.create_all(bind=engine)
 
+db_session = Session()
+
 first_user = db_session.query(User).first()
 if not first_user:
     u = User(email="johndoe@example.com", hashed_password="notreallyhashed")
     db_session.add(u)
     db_session.commit()
 
+db_session.close()
+
 
 # Utility
 def get_user(db_session, user_id: int):
@@ -51,6 +54,14 @@ app = FastAPI()
 
 
 @app.get("/users/{user_id}")
-def read_user(user_id: int):
-    user = get_user(db_session, user_id=user_id)
+def read_user(request: Request, user_id: int):
+    user = get_user(request._scope["db"], user_id=user_id)
     return user
+
+
+@app.middleware("http")
+async def close_db(request, call_next):
+    request._scope["db"] = Session()
+    response = await call_next(request)
+    request._scope["db"].close()
+    return response