The number of documents that matched the filter与筛选器匹配的文档数
The number of documents that were modified修改的文档数
The number of documents that were upserted已升迁的文档数
The identifier of the inserted document if an upsert took place如果发生升级，插入文档的标识符
Generated using TypeDoc
Indicates whether this write result was acknowledged.指示此写入结果是否已确认。If not, then all other members of this result will be undefined如果不是，则此结果的所有其他成员都将未定义