25
比如我在MongoDB的以下数据:MongoDB的总和查询
{ "_id" : ObjectId("524091f99c49c4c3f66b0e46"), "hour" : 10, "incoming", 100}
{ "_id" : ObjectId("5240a045dbeff33c7333aa51"), "hour" : 11, "incoming", 200}
{ "_id" : ObjectId("5240a2ecda0d37f35c618aca"), "hour" : 12, "incoming", 300}
现在我要查询“SUM的传入与11号 - 12”(结果应该是500),我怎么可能使用Mongo Shell来做到这一点?
检查淘汰MongoDB的[汇总框架](http://docs.mongodb.org/manual/reference/aggregation/)。特别是,请看['$ match'](http://docs.mongodb.org/manual/reference/aggregation/match/#pipe._S_match),['$ group'](http:// docs .mongodb.org/manual/reference/aggregation/group /#pipe._S_group)和['$ sum'](http://docs.mongodb.org/manual/reference/aggregation/sum/#grp._S_sum) 。 – llovett