Update main.py

main.py

@@ -27,6 +27,7 @@ class Mentor(Base):
 
     id = Column(Integer, primary_key=True)
     mentor_name = Column(String)
+    username = Column(String, unique=True)
     profile_photo = Column(LargeBinary)  
     description = Column(String)
     highest_degree = Column(String)
@@ -40,6 +41,9 @@ class Mentor(Base):
  
     stream = relationship("Stream", backref="mentors") 
 
+ 
+    stream = relationship("Stream", backref="mentors") 
+
 engine = create_engine(connection_string)
 Session = sessionmaker(bind=engine)