Node.js | MongoDB 連接

環境準備

MongoDB的安裝可以參閱Docker - 第十一章 | 安裝MongoDB。

顯示目前的資料庫清單：

> show dbs
admin   0.000GB
config  0.000GB
local   0.000GB

安裝 MongoDB 驅動

要使用Node.js訪問MongoDB資料庫，你需要一個MongoDB驅動程序。

1	npm install mongodb --save

連接資料庫

要在MongoDB中建立一個資料庫，首先我們需要建立一個MongoClient對象，然後配置好指定的URL和端口號。

如果資料庫不存在，MongoDB將建立資料庫並建立連接。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
  if (err) throw err;
  console.log("資料庫已建立!");
  db.close();
});

執行結果如下：

1
2
3

$ node test.js
(node:4753) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
資料庫已建立!

建立集合

使用createCollection()方法來建立集合：

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function (err, db) {
    if (err) throw err;
    console.log('資料庫已建立');
    var dbase = db.db("jjtest");
    dbase.createCollection('site', function (err, res) {
        if (err) throw err;
        console.log("建立集合!");
        db.close();
    });
});

執行結果如下：

$ node test.js
(node:4861) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
資料庫已建立
建立集合!

資料庫操作 (CURD)

與MySQL不同的是MongoDB會自動建立資料庫和集合，所以使用前我們不需要手動去建立。

插入資料

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var myobj = { name: "J.J.'s blogs", url: "morosedog.gitlab.io" };
    dbo.collection("site").insertOne(myobj, function(err, res) {
        if (err) throw err;
        console.log("資料插入成功");
        db.close();
    });
});

執行結果如下：

1
2
3

$ node test.js
(node:4872) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
資料插入成功

MongoDB客戶端：

> show dbs
admin   0.000GB
config  0.000GB
jjtest  0.000GB
local   0.000GB
> use jjtest
switched to db jjtest
> show tables
site
> db.site.find()
{ "_id" : ObjectId("5e44ef0cda14ed1308971ca7"), "name" : "J.J.'s blogs", "url" : "morosedog.gitlab.io" }
>

插入多筆資料

插入多條資料可以使用insertMany()。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var myobj =  [
        { name: "J.J.'s blogs", url: "morosedog.gitlab.io" },
        { name: 'Google', url: 'https://www.google.com'},
        { name: 'Facebook', url: 'https://zh-tw.facebook.com'}
       ];
    dbo.collection("site").insertMany(myobj, function(err, res) {
        if (err) throw err;
        console.log("插入的資料數量為: " + res.insertedCount);
        db.close();
    });
});

執行結果如下：

1
2
3

$ node test.js
(node:4977) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
插入的資料數量為: 3

MongoDB客戶端：

> use jjtest
switched to db jjtest
> db.site.find()
{ "_id" : ObjectId("5e44f141b5d2871371235873"), "name" : "J.J.'s blogs", "url" : "morosedog.gitlab.io" }
{ "_id" : ObjectId("5e44f141b5d2871371235874"), "name" : "Google", "url" : "https://www.google.com" }
{ "_id" : ObjectId("5e44f141b5d2871371235875"), "name" : "Facebook", "url" : "https://zh-tw.facebook.com" }

查詢資料

使用find()來查找資料，find()可以返回匹配條件的所有資料。

如果未指定條件，find()返回集合中的所有資料。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    dbo.collection("site"). find({}).toArray(function(err, result) {
        if (err) throw err;
        console.log(result);
        db.close();
    });
});

執行結果如下：

$ node test.js
(node:4989) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
[
  {
    _id: 5e44f141b5d2871371235873,
    name: "J.J.'s blogs",
    url: 'morosedog.gitlab.io'
  },
  {
    _id: 5e44f141b5d2871371235874,
    name: 'Google',
    url: 'https://www.google.com'
  },
  {
    _id: 5e44f141b5d2871371235875,
    name: 'Facebook',
    url: 'https://zh-tw.facebook.com'
  }
]

查詢條件為”J.J.’s blogs”：

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var whereStr = {"name":'J.J.\'s blogs'};
    dbo.collection("site").find(whereStr).toArray(function(err, result) {
        if (err) throw err;
        console.log(result);
        db.close();
    });
});

執行結果如下：

$ node test.js
(node:5011) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
[
  {
    _id: 5e44f141b5d2871371235873,
    name: "J.J.'s blogs",
    url: 'morosedog.gitlab.io'
  }
]

更新資料

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var whereStr = {"name":'J.J.\'s blogs'};
    var updateStr = {$set: { "url" : "https://morosedog.gitlab.io/" }};
    dbo.collection("site").updateOne(whereStr, updateStr, function(err, res) {
        if (err) throw err;
        console.log("資料更新成功");
        db.close();
    });
});

執行結果如下：

1
2
3

$ node test.js
(node:5028) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
資料更新成功

MongoDB客戶端：

> db.site.find()
{ "_id" : ObjectId("5e44f141b5d2871371235873"), "name" : "J.J.'s blogs", "url" : "https://morosedog.gitlab.io/" }
{ "_id" : ObjectId("5e44f141b5d2871371235874"), "name" : "Google", "url" : "https://www.google.com" }
{ "_id" : ObjectId("5e44f141b5d2871371235875"), "name" : "Facebook", "url" : "https://zh-tw.facebook.com" }
>

更新多筆資料

更新所有符合條件的資料資料可以使用updateMany()。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var whereStr = {"name":'J.J.\'s blogs'};
    var updateStr = {$set: { "url" : "https://morosedog.gitlab.io/" }};
    dbo.collection("site").updateMany(whereStr, updateStr, function(err, res) {
        if (err) throw err;
         console.log(res.result.nModified + " 條資料被更新");
        db.close();
    });
});

註：更新多筆資料就不特別示範了。

刪除資料

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";

MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var whereStr = {"name":'J.J.\'s blogs'};
    dbo.collection("site").deleteOne(whereStr, function(err, obj) {
        if (err) throw err;
        console.log("資料刪除成功");
        db.close();
    });
});

執行結果如下：

1
2
3

$ node test.js
(node:5074) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
資料刪除成功

MongoDB客戶端：

> use jjtest
switched to db jjtest
> db.site.find()
{ "_id" : ObjectId("5e44f141b5d2871371235873"), "name" : "J.J.'s blogs", "url" : "https://morosedog.gitlab.io/" }
{ "_id" : ObjectId("5e44f141b5d2871371235874"), "name" : "Google", "url" : "https://www.google.com" }
{ "_id" : ObjectId("5e44f141b5d2871371235875"), "name" : "Facebook", "url" : "https://zh-tw.facebook.com" }
>
>
>
> db.site.find()
{ "_id" : ObjectId("5e44f141b5d2871371235874"), "name" : "Google", "url" : "https://www.google.com" }
{ "_id" : ObjectId("5e44f141b5d2871371235875"), "name" : "Facebook", "url" : "https://zh-tw.facebook.com" }
>

刪除多筆資料

刪除所有符合條件的資料資料可以使用deleteMany()。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";

MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var whereStr = {"name":'J.J.\'s blogs'};
    dbo.collection("site").deleteMany(whereStr, function(err, obj) {
        if (err) throw err;
        console.log(obj.result.n + " 條資料被刪除");
        db.close();
    });
});

註：刪除多筆資料就不特別示範了。

刪除集合

使用drop()方法來刪除集合。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    dbo.collection("site").drop(function(err, delOK) {
        if (err) throw err;
        if (delOK) console.log("集合已刪除");
        db.close();
    });
});

執行結果如下：

1
2
3

$ node test.js
(node:5086) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
集合已刪除

MongoDB客戶端：

> use jjtest
switched to db jjtest
> show tables
site
>
>
> show tables
>

排序

使用sort()方法，該方法接受一個參數，規定是升序(1)還是降序(-1)。

1 2	{ type: 1 } // 按 type 字段升序 { type: -1 } // 按 type 字段降序

在開始之前，請先準備資料，主要是多了type的資料。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var myobj =  [
        { name: "J.J.'s blogs", url: "morosedog.gitlab.io", type: 1 },
        { name: 'Google', url: 'https://www.google.com', type: 2},
        { name: 'Facebook', url: 'https://zh-tw.facebook.com', type: 3}
       ];
    dbo.collection("site").insertMany(myobj, function(err, res) {
        if (err) throw err;
        console.log("插入的資料數量為: " + res.insertedCount);
        db.close();
    });
});

MongoDB客戶端：

> use jjtest
switched to db jjtest
> db.site.find()
{ "_id" : ObjectId("5e44f9b0e8a4cb13e7650b40"), "name" : "J.J.'s blogs", "url" : "morosedog.gitlab.io", "type" : 1 }
{ "_id" : ObjectId("5e44f9b0e8a4cb13e7650b41"), "name" : "Google", "url" : "https://www.google.com", "type" : 2 }
{ "_id" : ObjectId("5e44f9b0e8a4cb13e7650b42"), "name" : "Facebook", "url" : "https://zh-tw.facebook.com", "type" : 3 }
>

按type升序排列。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var mysort = { type: 1 };
    dbo.collection("site").find().sort(mysort).toArray(function(err, result) {
        if (err) throw err;
        console.log(result);
        db.close();
    });
});

執行結果如下：

$ node test.js
(node:5121) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
[
  {
    _id: 5e44f9b0e8a4cb13e7650b40,
    name: "J.J.'s blogs",
    url: 'morosedog.gitlab.io',
    type: 1
  },
  {
    _id: 5e44f9b0e8a4cb13e7650b41,
    name: 'Google',
    url: 'https://www.google.com',
    type: 2
  },
  {
    _id: 5e44f9b0e8a4cb13e7650b42,
    name: 'Facebook',
    url: 'https://zh-tw.facebook.com',
    type: 3
  }
]

按type降序排列。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    var mysort = { type: -1 };
    dbo.collection("site").find().sort(mysort).toArray(function(err, result) {
        if (err) throw err;
        console.log(result);
        db.close();
    });
});

執行結果如下：

$ node test.js
(node:5126) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
[
  {
    _id: 5e44f9b0e8a4cb13e7650b42,
    name: 'Facebook',
    url: 'https://zh-tw.facebook.com',
    type: 3
  },
  {
    _id: 5e44f9b0e8a4cb13e7650b41,
    name: 'Google',
    url: 'https://www.google.com',
    type: 2
  },
  {
    _id: 5e44f9b0e8a4cb13e7650b40,
    name: "J.J.'s blogs",
    url: 'morosedog.gitlab.io',
    type: 1
  }
]

查詢分頁

使用limit()方法，該方法只接受一個參數，指定了返回的條數。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    dbo.collection("site").find().limit(2).toArray(function(err, result) {
        if (err) throw err;
        console.log(result);
        db.close();
  });
});

執行結果如下：

$ node test.js
(node:5172) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
[
  {
    _id: 5e44f9b0e8a4cb13e7650b40,
    name: "J.J.'s blogs",
    url: 'morosedog.gitlab.io',
    type: 1
  },
  {
    _id: 5e44f9b0e8a4cb13e7650b41,
    name: 'Google',
    url: 'https://www.google.com',
    type: 2
  }
]

指定跳過的條數，可以使用skip()方法。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true }, function(err, db) {
    if (err) throw err;
    var dbo = db.db("jjtest");
    // 跳過前面兩條資料，讀取兩條資料
    dbo.collection("site").find().skip(2).limit(2).toArray(function(err, result) {
        if (err) throw err;
        console.log(result);
        db.close();
  });
});

執行結果如下：

$ node test.js
(node:5177) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
[
  {
    _id: 5e44f9b0e8a4cb13e7650b42,
    name: 'Facebook',
    url: 'https://zh-tw.facebook.com',
    type: 3
  }
]

註：礙於太多GIF圖檔，會造成網頁讀取緩慢，所以這邊就不再顯示示範。

補充

關於警告DeprecationWarning：不建議使用當前的URL字符串解析器，並將在以後的版本中將其刪除。
要使用新的解析器，請將選項{ useNewUrlParser: true , useUnifiedTopology: true}傳遞給MongoClient.connect。

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost:27017/jjtest";
 
MongoClient.connect(url, { useNewUrlParser: true , useUnifiedTopology: true}, function(err, db) {
  if (err) throw err;
  console.log("資料庫已建立!");
  db.close();
});

執行結果如下：

1 2	$ node test.js 資料庫已建立!

註：以上參考了
Node.js 连接 MongoDB
MongoDB 教程

Node.js | MySQL 連接

Node.js | 監控並透過Tomcat Manager重啟服務

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本文由J.J. Huang 創作，採用CC BY 3.0 TW協議進行許可。可自由轉載、引用，但需署名作者且註明文章出處。

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J.J. Huang 2020-02-13 Node.js 瀏覽次數：次 {{moment(1581555600000).fromNow()}}

Node.js | MongoDB 連接

環境準備

安裝 MongoDB 驅動

連接資料庫

建立集合

資料庫操作 (CURD)

插入資料

插入多筆資料

查詢資料

更新資料

更新多筆資料

刪除資料

刪除多筆資料

刪除集合

排序

查詢分頁

補充