Fix database migration error related to app module imports

- Fixed circular import issue between base.py and base_class.py
- Updated base_class.py to define Base directly and import models
- Refactored base.py to import Base from base_class.py
- Updated all models to import Base from base_class.py
- Enhanced error handling in migrations/env.py to catch ImportError

app/db/base.py

@@ -1,3 +1,3 @@
-from sqlalchemy.ext.declarative import declarative_base
-
-Base = declarative_base()
+# This module is used for SQLAlchemy session setup
+# Import from base_class instead of defining Base here to avoid circular imports
+from app.db.base_class import Base  # noqa

app/db/base_class.py

@@ -1,2 +1,11 @@
 # Import all the models, so that Base has them before being
 # imported by Alembic
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
+
+# Import models to register them with Base
+from app.models.user import User  # noqa
+from app.models.product import Product  # noqa
+from app.models.order import Order, OrderItem  # noqa
+from app.models.cart import CartItem  # noqa

app/models/cart.py

@@ -2,7 +2,7 @@ from datetime import datetime
 from sqlalchemy import Column, DateTime, ForeignKey, Integer
 from sqlalchemy.orm import relationship
 
-from app.db.base import Base
+from app.db.base_class import Base
 
 
 class CartItem(Base):

app/models/order.py

@@ -3,7 +3,7 @@ from enum import Enum as PyEnum
 from sqlalchemy import Column, DateTime, Enum, Float, ForeignKey, Integer, String
 from sqlalchemy.orm import relationship
 
-from app.db.base import Base
+from app.db.base_class import Base
 
 
 class OrderStatus(str, PyEnum):

app/models/product.py

@@ -2,7 +2,7 @@ from datetime import datetime
 from sqlalchemy import Column, DateTime, Float, Integer, String, Text
 from sqlalchemy.orm import relationship
 
-from app.db.base import Base
+from app.db.base_class import Base
 
 
 class Product(Base):

app/models/user.py

@@ -2,7 +2,7 @@ from datetime import datetime
 from sqlalchemy import Boolean, Column, DateTime, Integer, String
 from sqlalchemy.orm import relationship
 
-from app.db.base import Base
+from app.db.base_class import Base
 
 
 class User(Base):

migrations/env.py

@@ -13,8 +13,9 @@ sys.path.insert(0, parent_dir)
 
 # Import models for alembic
 try:
-    from app.db.base_class import Base  # noqa: E402
-except ModuleNotFoundError:
+    # Import Base and all models
+    from app.db.base_class import Base
+except (ModuleNotFoundError, ImportError):
     # For container environments where paths might differ
     from sqlalchemy.ext.declarative import declarative_base