remove topic id; topic children as json column

orm/topic.py

@@ -1,35 +1,24 @@
 from datetime import datetime
-from sqlalchemy import Table, Column, Integer, String, ForeignKey, DateTime, UniqueConstraint
+from sqlalchemy import Table, Column, Integer, String, ForeignKey, DateTime, JSON as JSONType
 from sqlalchemy.orm import relationship
 from orm.base import Base
 
-
-Connection = Table('topic_connections',
-	Base.metadata,
-    Column('child', Integer, ForeignKey('topic.id')),
-    Column('parent', Integer, ForeignKey('topic.id')),
-    UniqueConstraint('parent', 'child', name='unique_usage')
-)
-
 class TopicSubscription(Base):
 	__tablename__ = "topic_subscription"
 	
 	id = None
-	topic = Column(ForeignKey('topic.id'), primary_key = True)
+	topic = Column(ForeignKey('topic.slug'), primary_key = True)
 	user = Column(ForeignKey('user.id'), primary_key = True)
 	createdAt: str = Column(DateTime, nullable=False, default = datetime.now, comment="Created at")
 
 class Topic(Base):
 	__tablename__ = 'topic'
 
-	slug: str = Column(String, unique = True, nullable = False)
+	id = None
+
+	slug: str = Column(String, primary_key = True)
 	title: str = Column(String, nullable=False, comment="Title")
 	body: str = Column(String, nullable=True, comment="Body")
 	pic: str = Column(String, nullable=True, comment="Picture")
-	cat_id: str = Column(String, nullable=True, comment="Old Category ID")
-	# list of Topics where the current node is the "other party" or "child"
-	parents = relationship(lambda: Topic, secondary=Connection, primaryjoin=slug==Connection.c.parent, secondaryjoin=slug==Connection.c.child, viewonly=True)
-	# list of Topics where the current node is the "parent" 
-	children = relationship(lambda: Topic, secondary=Connection, primaryjoin=slug==Connection.c.child, secondaryjoin=slug==Connection.c.parent)
+	children = Column(JSONType, nullable=True, comment="list of children topics")
 	community = Column(ForeignKey("community.slug"), nullable=False, comment="Community")
-