数据集合： { "_id" : ObjectId(“5bac4d71f621081e1c15b7a6”), “notesData” : ObjectId(“5b8ca56f41c8b122444639db”), “userData” : ObjectId(“5b98729d75f1ef1708575269”), “status” : 0, “replyData” : [ { "_id" : ObjectId(“5bac4d71f621081e1c15b7a7”), “from” : null, “to” : ObjectId(“5b98729d75f1ef1708575269”), “content” : “你好，世界，评论功能已经完善！[吃瓜]”, “createTime” : ISODate(“2018-09-27T03:24:33.224Z”) }, { "_id" : ObjectId(“5bac4db2f621081e1c15b7a8”), “from” : ObjectId(“5b98729d75f1ef1708575269”), “to” : ObjectId(“5b7a777d8de91e20f0c3f712”), “content” : “恭喜啊[钢铁侠][吃瓜][吃瓜]”, “createTime” : ISODate(“2018-09-27T03:25:38.477Z”) }, { "_id" : ObjectId(“5baee1744df73e214c51b748”), “from” : ObjectId(“5b7a777d8de91e20f0c3f712”), “to” : ObjectId(“5b7cc3a86e289823248fd1a2”), “content” : “评论功能出现小bug 正在努力修复当中 费劲啊[允悲]”, “createTime” : ISODate(“2018-09-29T02:20:36.591Z”) } ], "__v" : 0 }
$unwind拆分后的数据为：------------------------------------------------------------------------------------- { "_id" : ObjectId(“5bac4d71f621081e1c15b7a6”), “notesData” : ObjectId(“5b8ca56f41c8b122444639db”), “userData” : ObjectId(“5b98729d75f1ef1708575269”), “status” : 0, “replyData” : { "_id" : ObjectId(“5bac4d71f621081e1c15b7a7”), “from” : null, “to” : ObjectId(“5b98729d75f1ef1708575269”), “content” : “你好，世界，评论功能已经完善！[吃瓜]”, “createTime” : ISODate(“2018-09-27T03:24:33.224Z”) }
}, { "_id" : ObjectId(“5bac4d71f621081e1c15b7a6”), “notesData” : ObjectId(“5b8ca56f41c8b122444639db”), “userData” : ObjectId(“5b98729d75f1ef1708575269”), “status” : 0, “replyData” : { "_id" : ObjectId(“5bac4d71f621081e1c15b7a7”), “from” : null, “to” : ObjectId(“5b98729d75f1ef1708575269”), “content” : “你好，世界，评论功能已经完善！[吃瓜]”, “createTime” : ISODate(“2018-09-27T03:24:33.224Z”) }
}
// 通过$unwind 单独把replyData数据 拆分成[{},{}]的形式，然后在$match 匹配某个时间段的数据 但是就是匹配不到数据？一下是我写得代码
Reply.aggregate([{$unwind: ‘$replyData’}, { $project: { _id: 1, notesData: 1, replyData: 1 } }, { $match: { $and: [{‘replyData.createTime’: {$gt: req.query.dataTime[1]}}, {‘replyData.createTime’: {$lt: req.query.dataTime[0]}}] } }, {$sort: {‘replyData.createTime’: -1}}]);
