我正在尝试在Mongodb中执行查询。我要执行的查询是根据日期(过去7天)查找集合中的所有订单，然后将价格与每个订单的嵌套对象相加。到目前为止，我有以下代码:收集/数据{"_id":"g32fYpydfSFDbFkoi","orderNumber":1234,"createdAt":ISODate("2016-01-12T13:50:17.559Z"),"productsInOrder":[{"category":"ambient","item":23982,"desc":"ErgonomicCottonSausages","quantity":"456","price":"0.54"