小编Alf*_*edo的帖子

我遇到了一个问题.我尝试查询此文档以获取"COL"数组之外的LOC标识符的数量和组的总和.

{
"_id" : ObjectId("57506d74c469888f0d631be6"),
"LOC" : "User001",
"COL" : [ 
    {
        "date" : "25/03/2016",
        "number" : "Folio009",
        "amount" : 100
    }, 
    {
        "date" : "25/04/2016",
        "number" : "Folio010",
        "amount" : 100
    }

]}

这个命令在mongo中有效,但我无法使用Pymongo包在Python中工作:

Mongo查询(工作)

db.perfiles.aggregate({"$unwind": "$COL"},
{ "$group": { _id: "$LOC", "sum" : {"$sum" : "$COL.amount" }}})

Pymongo(不工作)

from pymongo import MongoClient

client = MongoClient()

db = client['temporal']

docs = db.perfiles


pipeline = [{"$unwind": "$COL"},
     {"$group": {"_id": "$LOC", "count": {"$sum": "$COL.amount"}}}
          ]

list(db.docs.aggregate(pipeline))

有什么建议可以在Pymongo中查询同一个查询吗？谢谢!