mongo对分组数据进行排序

Posted 2022-01-08 pokid

分组之后希望按原字段进行排序，比如说时间戳，可以在分组数据中用$first显示原数据，然后在利用管道对该字段进行排序

参考：

db.xx.aggregate([
    "$match":"timestamp":    "$gte":1557813600,"$lte":1560492000,"service":"$in":["bauhinia","internal"],
    
        "$group":
            "_id":"service":"$service","timestamp":"$timestamp",
            "flow":$sum:$multiply:["$rate","$count"],
            "timestamp":"$first":"$timestamp",
            ,
    ,
    "$sort":"timestamp":1,
 ])

go语言代码参考

pipelines := []bson.M
        //如果 $match 位于管道的第一个阶段，可以利用索引来提高查询效率
        "$match": bson.M"timestamp": bson.M"$gte": float64(cursorTimeStamp), "$lte": float64(nowTimeStamp),"service":bson.M"$in":models.ServiceArr,
        "$group": bson.M
            "_id":  bson.M"service": "$service", "timestamp": "$timestamp",
            "flow": bson.M"$sum": bson.M"$multiply": []string"$rate", "$count",
            //额外的timestamp用于排序
            "timestamp":bson.M"$first":"$timestamp",
        ,
        "$sort":bson.M"timestamp":1,