old_contents: # -*- coding: utf-8 -*-
  from sqlalchemy import Column, Integer, Sequence, String, DateTime
  from sqlalchemy.ext.declarative import declarative_base
  
  from ..models import engine
  
  
  Base = declarative_base()
  
  
  class Link(Base):
      __tablename__ = 'link'
      id = Column(Integer, Sequence('link_id_seq'), primary_key=True)
      url = Column(String(1000))
      slug = Column(String(1000))
      description = Column(String(1000))
      create_time = Column(DateTime)
  
      def __init__(self, slug, url, description, create_time):
          self.url = url
          self.slug = slug
          self.description = description
          self.create_time = create_time
  
      def __repr__(self):
          return "<Link('%s','%s','%s', '%s')>" % (self.url, 
                                                   self.slug, self.description,
                                                   self.create_time)
  
  
  Link.metadata.create_all(engine)
  
new_contents: # -*- coding: utf-8 -*-
  from sqlalchemy import Column, Integer, Sequence, String, DateTime
  from sqlalchemy.ext.declarative import declarative_base
  
  from ..models import engine
  
  
  base = declarative_base()
  
  
  class Link(base):
      __tablename__ = 'link'
      id = Column(Integer, Sequence('link_id_seq'), primary_key=True)
      url = Column(String(1000))
      slug = Column(String(1000))
      description = Column(String(1000))
      create_time = Column(DateTime)
  
      def __init__(self, slug, url, description, create_time):
          self.url = url
          self.slug = slug
          self.description = description
          self.create_time = create_time
  
      def __repr__(self):
          repr = "<Link('{0}', '{1}', '{2}', '{3}')>".format(self.url, self.slug, self.description, self.create_time)
          return repr
          
  Link.metadata.create_all(engine)
  
subject: Update link.py