nodejs连接MongoDB及增删查改操作

//客户端
const MongoClient = require('mongodb').MongoClient;

//链接url
const url = 'mongodb://localhost:27017';

//数据库名
const dbName = 'test1'

//创建客户端
const client = new MongoClient(url, {useNewUrlParser:true});

//连接数据库
(async function() {
    await client.connect();
    console.log('连接成功');

//获取数据库
    const db = client.db(dbName);

//获取集合

    const fruitsCol = db.collection('fruits');

    /*
    插入: insertOne /insertMany
    */
//插入单条数据
    let r = await fruitsCol.insertOne(
        {name:'芒果',price:21}
        )
//插入多条数据
    await fruitsCol.insertMany(
        [{name:'菠萝蜜',price:122},
        {name:'西瓜',price:6.98},
        {name:'百香果',price:24.5,address:'广西省'}
]

    )
    /*
    * 查詢find({}).toArray
    * */
//查询数据.toArray()方法转换成数据对象
    let f = await fruitsCol.find({name:'西瓜'}).toArray();
    console.log(f)

    //聚合操作(重点) （https://www.runoob.com/mongodb/mongodb-aggregate.html）
    f = await fruitsCol.aggregate(
      [
          {$match: { name:'菠萝蜜' }},
        {$group:{_id:'$name', sum:{$sum:'$price'}}},
          {$group:{_id:'$name', avg:{$avg:'$price'}}},

      ]
    )
        .toArray();
    console.log(f)

    // db.mycol.aggregate([{$group : {_id : "$by_user", url : {$push: "$url"}}}])
    f =  await fruitsCol.aggregate(
        [
            {$match:{name:'百香果'}},
            {$group:{_id:'$name',address:{$push:'$address'}}}
        ]

    )
        .toArray();
    console.log(f)

    f = await fruitsCol.find({address:'广西省'}).toArray();
    console.log(f);


    /*
   * 更新操作 update({})
   * db.mycol.update([{})
   * collection.update is deprecated. Use updateOne, updateMany, or bulkWrite instead.
   * */
    // db.col.updateOne({'title':'MongoDB 教程'},{$set:{'title':'MongoDB'}})
    f = await fruitsCol.updateMany(
        {name:'百香果'},
        {$set:{name:'荔枝'}}
    );
    console.log("更新成功", f.result);

    console.log("更新成功", r.result);
        f = await fruitsCol.find({name:'荔枝'}).toArray();
        console.log(f)


    f = await fruitsCol.updateOne(
        {
        address:'广西省'
    },
        {$set:{address:'江西省'}})
    console.log(f.result);
    /*
    * 删除操作
    * db.mycol.update([{})
    * */

    f = await fruitsCol.deleteOne(
        {address:'江西省'}
    )
    console.log('删除成功',f.result)

    f = await fruitsCol.deleteMany({address:'广西省'})
    console.log('delete success...' ,f.result);

//输入文档


})()

1、连接

1.png

2、查询

2.png

3、更新

3.png

4、删除

4.png

5、在robo3t中查看

robo3.png