我有一个预订表，我想获得一个月内的预订数量，即按月分组。我很困惑如何从日期中获取月份。这是我的架构:{"_id":ObjectId("5485dd6af4708669af35ffe6"),"bookingid":1,"operatorid":1,...,"bookingdatetime":"2012-10-11T07:00:00Z"}{"_id":ObjectId("5485dd6af4708669af35ffe7"),"bookingid":2,"operatorid":1,...,"bookingdatetime":"2014-07-26T05:00:00Z"}{"_id":Obj

我有一个预订表，我想获得一个月内的预订数量，即按月分组。我很困惑如何从日期中获取月份。这是我的架构:{"_id":ObjectId("5485dd6af4708669af35ffe6"),"bookingid":1,"operatorid":1,...,"bookingdatetime":"2012-10-11T07:00:00Z"}{"_id":ObjectId("5485dd6af4708669af35ffe7"),"bookingid":2,"operatorid":1,...,"bookingdatetime":"2014-07-26T05:00:00Z"}{"_id":Obj