fix part 2

backend/app/database/session.py

@@ -1,27 +1,33 @@
 """Database session management."""
 
-from sqlalchemy import create_engine
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
 from sqlalchemy.orm import sessionmaker
 
 from app.core.config import settings
 
-# Create SQLAlchemy engine
-engine = create_engine(
-    str(settings.DATABASE_URL),
+# Convert sync DATABASE_URL to async (replace postgresql:// with postgresql+asyncpg://)
+async_database_url = str(settings.DATABASE_URL).replace("postgresql://", "postgresql+asyncpg://")
+
+# Create async SQLAlchemy engine
+engine = create_async_engine(
+    async_database_url,
     pool_size=settings.DATABASE_POOL_SIZE,
     max_overflow=settings.DATABASE_MAX_OVERFLOW,
     pool_pre_ping=True,  # Verify connections before using
     echo=settings.DEBUG,  # Log SQL queries in debug mode
 )
 
-# Create session factory
-SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+# Create async session factory
+SessionLocal = sessionmaker(
+    bind=engine,
+    class_=AsyncSession,
+    autocommit=False,
+    autoflush=False,
+    expire_on_commit=False,
+)
 
 
-def get_db():
-    """Dependency for getting database session."""
-    db = SessionLocal()
-    try:
-        yield db
-    finally:
-        db.close()
+async def get_db():
+    """Dependency for getting async database session."""
+    async with SessionLocal() as session:
+        yield session