go 检查字符是否在结构体中

immutableT := reflect.TypeOf(Device{})
if _, ok := immutableT.FieldByName(columnKey); ok {
   db.Order(clause.OrderByColumn{Column: clause.Column{Name: columnKey}, Desc: order == "descend"})
} else {
   errors.New("order by 中 该字段不存在", columnKey)
}