Db.getcollection ('collection').find({"request. User_id ":12}) db.getCollection('collection').find({"request.user_id":12,"request.city_id":12})) Db.getcollection ('collection').find({$or:["request.user_id":12,"request.city_id":12]})) db.getCollection('collection').find({"request.id":12}).sort({"request.create_at":-1})Copy the code