feat: deal group

models/deal_group.py

@@ -0,0 +1,34 @@
+from typing import TYPE_CHECKING, Optional
+
+from sqlalchemy import ForeignKey, Table, Column
+from sqlalchemy.orm import mapped_column, Mapped, relationship
+
+from models import BaseModel
+
+if TYPE_CHECKING:
+    from models import Deal
+
+
+class DealGroup(BaseModel):
+    __tablename__ = 'deal_groups'
+    id: Mapped[int] = mapped_column(
+        primary_key=True
+    )
+    name: Mapped[Optional[str]] = mapped_column(
+        nullable=True
+    )
+    lexorank: Mapped[str] = mapped_column(
+        nullable=False
+    )
+    deals: Mapped["Deal"] = relationship(
+        back_populates='group',
+        secondary='deal_relations'
+    )
+
+
+deal_relations = Table(
+    'deal_relations',
+    BaseModel.metadata,
+    Column('deal_id', ForeignKey('deals.id'), primary_key=True, unique=True),
+    Column('group_id', ForeignKey('deal_groups.id'), primary_key=True)
+)