Fix deprecation warnings

- Update SQLAlchemy to use declarative_base from orm module
- Migrate Pydantic models to v2 ConfigDict
- Replace on_event with lifespan context manager

Author: christosm-dev

app/database.py

@@ -1,6 +1,5 @@
 from sqlalchemy import create_engine, Column, Integer, String, DateTime
-from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import declarative_base, sessionmaker
 from datetime import datetime
 
 SQLALCHEMY_DATABASE_URL = "sqlite:///./notes.db"

app/main.py

@@ -1,16 +1,21 @@
 from fastapi import FastAPI, Depends, HTTPException
 from sqlalchemy.orm import Session
 from typing import List
+from contextlib import asynccontextmanager
 
 from .database import get_db, init_db, NoteDB
 from .models import Note, NoteCreate, NoteUpdate
 
-app = FastAPI(title="Notes API", version="0.1.0")
 
-
-@app.on_event("startup")
-def startup_event():
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    # Startup
     init_db()
+    yield
+    # Shutdown (if needed in the future)
+
+
+app = FastAPI(title="Notes API", version="0.1.0", lifespan=lifespan)
 
 
 @app.get("/")

app/models.py

@@ -1,4 +1,4 @@
-from pydantic import BaseModel
+from pydantic import BaseModel, ConfigDict
 from datetime import datetime
 from typing import Optional
 
@@ -14,10 +14,9 @@ class NoteUpdate(BaseModel):
 
 
 class Note(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+    
     id: int
     title: str
     content: str
     created_at: datetime
-
-    class Config:
-        from_attributes = True