node.js连接mongodb

看此篇文章前如若你不了解也不会简单运用mongodb请戳这里
1.安装mongodb依赖，这里我们安装v2.2.33版本，如果之前有遇到过db.collection is not function 其实只是mongodb库版本的问题(桌面建立fml文件)

我的项目文件名为fml
C:\Users\admin\Desktop\fml> npm install mongodb@2.2.33

2.插入数据
在fml中新建node-mongodb.js,并复制黏贴下面代码

var MongoClient = require('mongodb').MongoClient;
// 连接数据库 字符串形式
var DB_CONNECT_STR = 'mongodb://localhost:27017/fengml'; 
var insertData = function(db, callback) {  
    //连接到表 fmlsite
    var collect = db.collection('fmenglsite');
    //插入数据
    var data = [{"author":"风慕李","url":"http://www.jianshu.com/u/96432503edfd","description":"good good study"}];
    collect.insert(data, function(err, result) { 
        if(err){
            console.log('Error:'+ err);
            return;
        }     
        callback(result);
    });
}
MongoClient.connect(DB_CONNECT_STR, function(err, db) {
    console.log("connect server success！");
    insertData(db, function(result) {
        console.log(result);
        db.close();
    });
});

如若你也是vscode的使用者，快捷键Ctrl+`执行node node-mongodb.js

 C:\Users\admin\Desktop\fml> node node-mongodb.js
connect server success！
{ result: { ok: 1, n: 1 },
  ops:
   [ { author: '风慕李',
       url: 'http://www.jianshu.com/u/96432503edfd',
       description:'good good study',
       _id: 5a28ffd2241ba235a4d51535 } ],
  insertedCount: 1,
  insertedIds: [ 5a28ffd2241ba235a4d51535 ] }

你也可以通过mongodb客户端使用show dbs等语法查看（忘记了就戳这里）
3.查询数据

var MongoClient = require('mongodb').MongoClient;
var DB_CONNECT_STR = 'mongodb://localhost:27017/fengml';  
var searchData = function(db, callback) {  
  //连接到表  
  var collection = db.collection('fengmlsite');
  //查询数据
  var dataStr = {"description":'good good study'};
  collection.find(dataStr).toArray(function(err, result) {
    if(err){
      console.log('Error:'+ err);
      return;
    }    
    callback(result);
  });
}
MongoClient.connect(DB_CONNECT_STR, function(err, db) {
  console.log("connect server success");
  searchData(db, function(result) {
    console.log(result);
    db.close();
  });
});

结果打印（如果返回为[]，或许你需要等待一会，或者)

C:\Users\admin\Desktop\fml> node node-search.js
connect server success
[ { _id: 5a2907838e6f0939908741a9,
    author: '风慕李',
    url: 'http://www.jianshu.com/u/96432503edfd',
    description: 'good good study' } ]

4.更新数据

var MongoClient = require('mongodb').MongoClient;
var DB_CONNECT_STR = 'mongodb://localhost:27017/fengml';
var updateData = function(db, callback) {  
    //连接到表  
    var collection = db.collection('fengmlsite');
    //更新数据
    var dataStr = {"author":'风慕李'};
    var updateStr = {$set: { "description" : "day day up" }};
    collection.update(dataStr,updateStr, function(err, result) {
        if(err){
            console.log('Error:'+ err);
            console.log(0)
            return;
        }     
        callback(result);
    });
}
 MongoClient.connect(DB_CONNECT_STR, function(err, db) {
    console.log("connect server success");
    updateData(db, function(result) {
        console.log(result);
        db.close();
    });
});

终端输入

C:\Users\admin\Desktop\fml> node node-update.js
我们重新运行node-search.js会发现结果为空，我们在将node-search.js的查询条件datastr改为 {"author":'风慕李'}。你会看到如下结果：
C:\Users\admin\Desktop\fml> node node-search.js
connect server success
[ { _id: 5a2907838e6f0939908741a9,
    author: '风慕李',
    url: 'http://www.jianshu.com/u/96432503edfd',
    description: 'day day up' } ]
    这时你会看到description字段已经被更新了

5.删除数据

var MongoClient = require('mongodb').MongoClient;
var DB_CONNECT_STR = 'mongodb://localhost:27017/fengml';    
 var delData = function(db, callback) {  
  //连接到表  
  var collection = db.collection('fengmlsite');
  //删除数据
  var dataStr = {"author":'风慕李'};
  collection.remove(dataStr, function(err, result) {
    if(err){
      console.log('Error:'+ err);
      return;
    }     
    callback(result);
  });
}
 
MongoClient.connect(DB_CONNECT_STR, function(err, db) {
  console.log("connect server success！");
  delData(db, function(result) {
    console.log(result);
    db.close();
  });
});

终端输入

C:\Users\admin\Desktop\fml> node node-delete.js
我们重新运行node-search.js会发现结果为空,说明删除成功了

注：开始前记得运行mongodb服务（手动运行mongod.exe和mongo.exe或者用命令）
PS：如此一来，前端就可以愉快的操作数据库了，对于前端的我们来说开心不言而喻。

原文地址 https://gitee.com/wangFengJ/node/tree/master/node-mongodb