code: func (engine *Engine) Asc(colNames ...string) *Session {
  	session := engine.NewSession()
  	session.isAutoClose = true
  	return session.Asc(colNames...)
  }
docs: // Asc will generate "ORDER BY column1,column2 Asc"
  // This method can chainable use.
  //
  //        engine.Desc("name").Asc("age").Find(&users)
  //        // SELECT * FROM user ORDER BY name DESC, age ASC
  //