feat: assignment of employees to deals

models/deal.py

@@ -108,6 +108,8 @@ class Deal(BaseModel):
     pallets: Mapped[list[Pallet]] = relationship(back_populates='deal', lazy='selectin')
     boxes: Mapped[list[Box]] = relationship(back_populates='deal', lazy='selectin')
 
+    assignments: Mapped[list['Assignment']] = relationship(back_populates='deal', lazy='selectin')
+
 
 class DealStatusHistory(BaseModel):
     __tablename__ = 'deals_status_history'
@@ -126,3 +128,14 @@ class DealStatusHistory(BaseModel):
     next_status_deadline = Column(DateTime,
                                   comment='Дедлайн до которого сделку нужно перевести на следующий этап')
     comment = Column(String, nullable=False, comment='Коментарий', server_default='')
+
+
+class Assignment(BaseModel):
+    __tablename__ = 'assignments'
+    user_id: Mapped[int] = mapped_column(ForeignKey('users.id'), primary_key=True)
+    user: Mapped['User'] = relationship('User', back_populates='assignments', lazy='selectin')
+
+    deal_id: Mapped[int] = mapped_column(ForeignKey('deals.id'), primary_key=True)
+    deal: Mapped[Deal] = relationship('Deal', back_populates='assignments', lazy='selectin')
+
+    created_at: Mapped[datetime] = mapped_column()