Fix circular import issue in database models

- Created a dedicated base_class.py file to define the SQLAlchemy Base
- Updated all models to import Base from base_class.py instead of session.py
- Modified migrations/env.py to properly import models and Base
- Fixed circular dependency between models and base classes

app/db/base.py

@@ -1,2 +1,9 @@
 # Import all the models, so that Base has them before being
 # imported by Alembic
+from app.db.base_class import Base  # noqa
+
+# Import all the models to ensure they are registered with SQLAlchemy
+from app.models.user import User  # noqa
+from app.models.post import Post  # noqa
+from app.models.comment import Comment  # noqa
+from app.models.tag import Tag, post_tag  # noqa

app/db/base_class.py

@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()

app/db/session.py

@@ -1,9 +1,9 @@
 from sqlalchemy import create_engine
-from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import sessionmaker
 from pathlib import Path
 import os
 
+
 # Check if we're running in the container environment
 IN_CONTAINER = os.path.exists('/app/repo')
 
@@ -23,6 +23,4 @@ engine = create_engine(
     SQLALCHEMY_DATABASE_URL,
     connect_args={"check_same_thread": False}
 )
-SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
-
-Base = declarative_base()

app/models/comment.py

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

app/models/post.py

@@ -2,7 +2,7 @@ from datetime import datetime
 from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Boolean
 from sqlalchemy.orm import relationship
 
-from app.db.session import Base
+from app.db.base_class import Base
 from app.models.tag import post_tag
 
 

app/models/tag.py

@@ -1,7 +1,7 @@
 from sqlalchemy import Column, Integer, String, Table, ForeignKey
 from sqlalchemy.orm import relationship
 
-from app.db.session import Base
+from app.db.base_class import Base
 
 # Association table for the many-to-many relationship between posts and tags
 post_tag = Table(

app/models/user.py

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

migrations/env.py

@@ -13,12 +13,18 @@ sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
 
 try:
     # Try to import using the container path structure
-    from app.db.base import Base
+    # First, import the Base class
+    from app.db.base_class import Base
+    # Then import the models to ensure they're registered with SQLAlchemy
+    import app.db.base  # noqa: F401
 except ImportError:
     # If that fails, try to import using the local path structure
     project_root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
     sys.path.insert(0, project_root)
-    from app.db.base import Base
+    # First, import the Base class
+    from app.db.base_class import Base
+    # Then import the models to ensure they're registered with SQLAlchemy
+    import app.db.base  # noqa: F401
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.