Indicates whether this write result was acknowledged. If not, then all other members of this result will be undefined指示此写入结果是否得到确认。如果不是，则此结果的所有其他成员都将是未定义的
The identifier that was inserted. If the server generated the identifier, this value will be null as the driver does not have access to that data插入的标识符。如果服务器生成了标识符，则此值将为null，因为驱动程序无权访问该数据
Indicates whether this write result was acknowledged. If not, then all other members of this result will be undefined指示此写入结果是否得到确认。如果不是，则此结果的所有其他成员都将是未定义的