📅  最后修改于: 2022-03-11 14:57:39.100000             🧑  作者: Mango
db.collection.aggregate([
{"$group" : { "_id": "$name", "count": { "$sum": 1 } } },
{"$match": {"_id" :{ "$ne" : null } , "count" : {"$gt": 1} } },
{"$project": {"name" : "$_id", "_id" : 0} }
]);