链接mongodb

文章目录

1. 1. 链接数据库
2. 2. 插入文档
3. 3. 修改文档
4. 4. 删除
5. 5. 查询

链接数据库

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

var url = 'mongodb://localhost:27017/myproject'
MongoClient.connect(url,function(err,db)){
	assert.equal(null,err);	// 如果err == null 继续执行
	console.log('Connected correctly to server');

	db.close();
}

插入文档

var insertDocument = function(db,callback) {
	var collection = db.collection('document');
	collection.insert([{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 document collection");
    	callback(result);
	});
}

可以在连接时增加

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() {
    db.close();
  });
});

修改文档

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.update({ 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);
  });  
}

也可以在连接时回调

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

删除

var removeDocument = function(db, callback) {
  // Get the documents collection
  var collection = db.collection('documents');
  // Insert some documents
  collection.remove({ 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 correctly to server");

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

查询

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);
    assert.equal(2, docs.length);
    console.log("Found the following records");
    console.dir(docs)
    callback(docs);
  });      
}

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