feat(models): add basic database structure

7project/backend/app/models/user.py

@@ -1,7 +1,13 @@
 from sqlalchemy import Column, String
+from sqlalchemy.orm import relationship
 from fastapi_users.db import SQLAlchemyBaseUserTableUUID
 from app.core.base import Base
 
+
 class User(SQLAlchemyBaseUserTableUUID, Base):
     first_name = Column(String(length=100), nullable=True)
     last_name = Column(String(length=100), nullable=True)
+
+    # Relationship
+    transactions = relationship("Transaction", back_populates="user")
+    categories = relationship("Category", back_populates="user")