如何实现将 MongoDB中group分组后的结果，再存入到mongo数据库中？？？？

Question

先通过mongo中的聚合函数：group（）后返回的是DBObject 对象，我想将其存入另一个集合中，怎么办？？？

Answer 1

Later, I figured it out myself, just put it directly into a document and insert it into the collection. .

Answer 2

collection.aggregate([
    {
        '$match': {}
    },
    {
        '$group': {}
    }
], {
    out: 'OtherCollection'
})

Requires MongoDB 2.6+
And every time you go out, the previous data will be erased
If you don’t want it to be erased, insert the structures into a new collection in batches