text: from app.extensions import db
  
  
  class BaseModel(db.Model):
      __abstract__ = True
      id = db.Column(db.Integer, primary_key=True, autoincrement=True)
  
      def save(self):
          try:
              db.session.add(self)
              db.session.commit()
              return True
          except Exception as e:
              print(e)
              return False
  
      def delete(self):
          try:
              db.session.delete(self)
              db.session.commit()
              return True
          except Exception as e:
              print(e)
              return False
  
  
  class User(BaseModel):
      __tablename__ = "userModel"
      id = db.Column(db.Integer, primary_key=True, autoincrement=True)
      userName = db.Column(db.String(16), unique=True)
      userDescription = db.Column(db.String(128), nullable=True)
      userID = db.Column(db.String(16))
  
  
  class ChangeLog(BaseModel):
      __tablename__ = "changeLog"
      id = db.Column(db.Integer, primary_key=True, autoincrement=True)
      date = db.Column(db.String(16))
      version = db.Column(db.String(16))
      status = db.Column(db.String(16))
      description = db.Column(db.String(128))
  
  
  class Feedback(BaseModel):
      __tablename__ = "feedback"
      id = db.Column(db.Integer, primary_key=True, autoincrement=True)
      contact_details = db.Column(db.String(1000))
      description = db.Column(db.String(1000))
      is_resolved = db.Column(db.String(1000), default = "未解决")
  
  # 主页/高考/数学/数学相关专栏排名，目前排名第二的宋冰的菠萝斑马居住指南，其内容与数学无关。
  # QQ:984552746
  