Создание и первичная инициализация базы даных успешно завершена. Наполнение демо-данными прошло без ошибок

db/schemas/toolkit.py

@@ -2,7 +2,7 @@ from datetime import datetime
 from sqlalchemy import Column, DateTime, ForeignKey, Integer, String, Text
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import relationship
-from db import Base
+from db import Base, CRUD
 import utils
 
 
@@ -15,7 +15,11 @@ class Toolkit(Base):
     specifications = Column(JSONB, default={})
     category_id = Column(Integer, ForeignKey("categories.id", ondelete="CASCADE"))
     category_data = relationship(
-        "Category", cascade="all, delete-orphan", lazy="joined", uselist=False
+        "Category",
+        cascade="all, delete-orphan",
+        lazy="joined",
+        uselist=False,
+        single_parent=True,
     )
     image = Column(JSONB)
     quantity_min = Column(Integer, nullable=True)
@@ -34,11 +38,7 @@ class Toolkit(Base):
         return utils.toDict(self)
 
     async def save(self):
-        from db import CRUD
-
         return await CRUD.create(self, refresh=True)
 
     async def edit(id: int, **kwargs):
-        from db import CRUD
-
         return await CRUD.update(Toolkit, id, **kwargs)