MongoDB简单使用

介绍

MongoDB 是一个免费的开源跨平台面向文档的 NoSQL 数据库。

安装

docker pull mongo

下载最新版本的镜像

docker run -d --name mongo -e MONGO_INITDB_ROOT_USERNAME=root -e MONGO_INITDB_ROOT_PASSWORD=xxx123 -p 27017:27017 mongo

设置初始账号和密码，注意开启防火墙对27017端口的限制

使用

windows客户端下载
MongoDB Shell Download

mongosh --host=ip --port=27017 -u=root -p=xxx123

增删改查

show dbs //显示所有数据库，如果db中没有数据，不显示，
use test_info //切换到test_info，db不存在就创建
db.movies.insertOne({title:"The First",year:2020}) //插入一条记录，会自动添加 _id 字段
db.movies.insertMany([{title:"The First",year:2020}]) //插入多条记录
db.movies.find({title:{$regex:"The"})//数据查询，正则表达式匹配，类似mysql的like
db.movies.find({year:{$gt:2010})//查询年份大于2010的电影
db.movies.find({year:2010})//查询年份等于2010的电影 相当于 db.movies.find({year:{$eq:2010}})
db.movies.updateOne({year:2020},{$set:{title:"The2"}}) //查询year为2020的记录(匹配到的第一条),title更新为The2
db.movies.updateMany({year:2020},{$set:{title:"The2"}}) //查询year为2020的记录(匹配到的多条),title更新为The2
db.movies.deleteOne({year:2020}) //删除year为2020的匹配到的第一条
db.movies.deleteMany({year:2020}) //删除year为2020的匹配到的多条
show collections //查询表

db类似mysql的数据库，不存在就创建
movies类似mysql的表，不存在就创建

用户及权限

use test_info
db.createUser({user:"root2",pwd:"xxx123",roles:[{role:"dbOwner",db:"test_info"},{role:"dbOwner",db:"admin"}]}) //在当前库(test_info)下创建用户及授权
show users //显示当前库下的用户

哪个库创建的用户必须在哪个库做认证

mongosh --host=ip --port=27017 -u=root2 -p=xxx123 admin //Authentication failed. 因为root2是在test_info库下创建的
mongosh mongodb://root2:xxx123@ip:27017/admin //Authentication failed. 因为root2是在test_info库下创建的
mongosh mongodb://root2:xxx123@ip:27017/test_info //Authentication Successfully.

Java客户端

<dependency>
  <groupId>org.mongodb</groupId>
  <artifactId>mongodb-driver-sync</artifactId>
  <version>4.8.2</version>
</dependency>

import com.mongodb.BasicDBObject;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Filters;
import org.bson.Document;
import org.bson.conversions.Bson;

import java.util.Collections;

public class TestMongoDBClient {
    public static void main(String[] args) {
//        testDelete();
        testFind();
    }

    private static void testDelete() {
        MongoCollection<Document> mongoCollection = mongoCollection();
        BasicDBObject queryObj = new BasicDBObject();
        queryObj.put("year", new BasicDBObject("$gt", 2020));
        mongoCollection.deleteOne(queryObj);
    }

    private static void testUpdate() {
        MongoCollection<Document> mongoCollection = mongoCollection();
        BasicDBObject queryObj = new BasicDBObject();
        queryObj.put("year", new BasicDBObject("$gt", 2020));
        BasicDBObject setObj = new BasicDBObject();
        setObj.put("$set", new BasicDBObject("title", "The First22"));
        mongoCollection.updateMany(queryObj, setObj);
    }

    private static void testInsert() {
        MongoCollection<Document> mongoCollection = mongoCollection();
        Document document = new Document();
        document.put("title", "THe fisrt");
        document.put("year", 2023);
        mongoCollection.insertMany(Collections.singletonList(document));
    }

    private static void testFind() {
        MongoCollection<Document> mongoCollection = mongoCollection();
        //两种拼接查询条件的方式，第一种
        BasicDBObject queryObj = new BasicDBObject();
        queryObj.put("year", new BasicDBObject("$gt", 2020));
        //两种拼接查询条件的方式，第二种
        Bson filter = Filters.gte("year", 2020);
        FindIterable<Document> findIterable = mongoCollection.find(filter);
        for (Document document : findIterable) {
            System.out.println(document);
        }
    }

    private static MongoCollection<Document> mongoCollection() {
        MongoClient mongoClient = mongoClient();
        MongoDatabase mongoDatabase = mongoClient.getDatabase("test_info");
        return mongoDatabase.getCollection("movies");
    }

    private static MongoClient mongoClient() {
        //mongodb://[username:password@]host[/[database][?options]]
        return MongoClients.create("mongodb://root2:xxx123@ip/test_info");
    }
}

参考

CRUD操作命令
MongoDB Driver 3.8 Documentation