nodejs中使用mongodb quickstart

nodejs中使用mongodb quickstart

node 中使用mongodb的quick start.整理的官网crud简单例子.

在百度找了几篇帖子都有问题,所以直接看官网了.

连接MondoDB

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';

// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  db.close();
});

新建数据

使用insertMany新建数据.mongodb中没有关系数据库中行的概念,最相近的概念是document.

var insertDocuments = function(db, callback) {
  // Get the documents collection
  var collection = db.collection('documents');
  // Insert some documents
  collection.insertMany([
    {a : 1}, {a : 2}, {a : 3}
  ], function(err, result) {
    assert.equal(err, null);
    assert.equal(3, result.result.n);
    assert.equal(3, result.ops.length);
    console.log("Inserted 3 documents into the collection");
    callback(result);
  });
}

The insert command returns an object with the following fields:

• result Contains the result document from MongoDB
• ops Contains the documents inserted with added _id fields
• connection Contains the connection used to perform the insert

建立连接后调用

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  insertDocuments(db, function() {
    db.close();
  });
});

读取collection中的数据

var findDocuments = function(db, callback) {
  // Get the documents collection
  var collection = db.collection('documents');
  // Find some documents
  collection.find({}).toArray(function(err, docs) {
    assert.equal(err, null);
    console.log("Found the following records");
    console.log(docs)
    callback(docs);
  });
}

这样会查询collection中的全部数据.我们把dindDocuments添加到MongoClient.connect的回调中

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected correctly to server");

  insertDocuments(db, function() {
    findDocuments(db, function() {
      db.close();
    });
  });
});

是的,collection.find是可以指定查询条件的

var findDocuments = function(db, callback) {
  // Get the documents collection
  var collection = db.collection('documents');
  // Find some documents
  collection.find({'a': 3}).toArray(function(err, docs) {
    assert.equal(err, null);
    console.log("Found the following records");
    console.log(docs);
    callback(docs);
  });
}

更新数据

使用updateOne进行单(document,不是行)数据的更新

var updateDocument = function(db, callback) {
  // Get the documents collection
  var collection = db.collection('documents');
  // Update document where a is 2, set b equal to 1
  collection.updateOne({ a : 2 }
    , { $set: { b : 1 } }, function(err, result) {
    assert.equal(err, null);
    assert.equal(1, result.result.n);
    console.log("Updated the document with the field a equal to 2");
    callback(result);
  });
}

加入MongoClient.connect的回调看结果:

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  insertDocuments(db, function() {
    updateDocument(db, function() {
      db.close();
    });
  });
});

删除document

类似查询的方式使用deleteOne删除document

var removeDocument = function(db, callback) {
  // Get the documents collection
  var collection = db.collection('documents');
  // Insert some documents
  collection.deleteOne({ a : 3 }, function(err, result) {
    assert.equal(err, null);
    assert.equal(1, result.result.n);
    console.log("Removed the document with the field a equal to 3");
    callback(result);
  });
}

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  insertDocuments(db, function() {
    updateDocument(db, function() {
      removeDocument(db, function() {
        db.close();
      });
    });
  });
});

添加索引

跟关系数据库一样添加索引可以提高查询效率

var indexCollection = function(db, callback) {
  db.collection('documents').createIndex(
    { "a": 1 },
      null,
      function(err, results) {
        console.log(results);
        callback();
    }
  );
};

var MongoClient = require('mongodb').MongoClient
  , assert = require('assert');

// Connection URL
var url = 'mongodb://localhost:27017/myproject';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
  assert.equal(null, err);
  console.log("Connected successfully to server");

  insertDocuments(db, function() {
    indexCollection(db, function() {
      db.close();
    });
  });
});

原文地址: http://mongodb.github.io/node-mongodb-native/2.2/quick-start/