我如何在MongoDB中执行组，排序和限制聚合

Question

我的收藏是这样的:

"_id": ObjectId(""),
"score": 500,
"year": 2015,
"batch": 1
"location": "Shenzhen"

我要做的是:

1. group with key batch year location
2. sort with score asc
3. 获取各组top 10 id, year, batch, location, score

Answer 1

使用聚合框架:

db.collection.aggregate(
    {$group:{...}},
    {$sort:{...}})
    {$limit: 10}
);