# insert db.person.insert({ "name": "kelvin", "age": 35 }) db.person.insert({ "name": "huahua", "age": 25 }) db.person.insert({ "name": "xiaomeng", "age": 24 }) db.person.insert({ "name": "laozhang", "age": 32 }) # select db.person.find() db.person.count() db.person.find({ "name": "kelvin" }) # update db.person.update({ "name": "laozhang" }, { "name": "oldzhang", "age": 33 }) # delete db.person.remove({ "name": "oldzhang" })