寫在前面：
最近讀了一本ES6的書，算是開啟了我轉型到js前端領域的一個契機，感概技術發展的如此迅速，於是又囫圇吞棗的學了reactjs，nodejs，mongodb基礎知識。一直忙著學習，也沒有騰出時間總結，這次在學習nodejs操作mongodb增刪改查基礎dao層操作時，自己照葫蘆畫瓢封裝了兩個模組，對於初學者也好理解，可以對比著看，使用起來也比較簡單，提供給大家做做參考，不吝賜教。

模組一
命名為MongoDBHandler.js

function MongoDB(MongoClient,url,dbName,collectionName){
    this.MongoClient = MongoClient;
    this
 
.url= url;
    this.dbName = dbName;
    this.collection = collectionName;
};
//連線資料庫
MongoDB.prototype.connect = function(url,callback){
    if(!url){
        return;
    }
    this.MongoClient.connect(url,function(err,db){
        callback(err,db);
        db.close();
    });
}
//插入單條資料
MongoDB.prototype.insertOne = function
 
(oneObj,callback){
    let dbName = this.dbName;
    let collection = this.collection;
    this.connect(this.url,function(err,db){
        var client = db.db(dbName);
        client.collection(collection).insertOne(oneObj, function(err, res) {
            if (err) throw err;
            console.log("單個文件插入成功"
 
);
            if(callback){
                callback(err,res);
            }
        });
    });
}
//批量插入
MongoDB.prototype.insertMany = function(objs,callback){
    if(!Array.isArray(objs)){
        throw new Error("非陣列，型別不匹配!");
        return;
    }

    let dbName = this.dbName;
    let collection = this.collection;
    this.connect(this.url,function(err,db){
        var client = db.db(dbName);
        client.collection(collection).insertMany(objs, function(err, res) {
            if (err) throw err;
            console.log("批量文件插入成功");
            if(callback){
                callback(err,res);
            }
        });
    });
}
//查詢指定條件下的資料
MongoDB.prototype.find = function(whereStr,callback){
    let dbName = this.dbName;
    let collection = this.collection;
    this.connect(this.url,function(err,db){
        if (err) throw err;
        var client = db.db(dbName);
        client.collection(collection).find(whereStr).toArray(function(err, result) {
            if (err) throw err;
            console.log(result);
            if(callback){
                callback(err,result);
            }
        });
    });
}
//刪除
MongoDB.prototype.remove = function(whereStr,callback){
    let dbName = this.dbName;
    let collection = this.collection;
    this.connect(this.url,function(err,db){
        if (err) throw err;
        var client = db.db(dbName);
        client.collection(collection).remove(whereStr,function(err, result) {
            if (err) throw err;
            console.log(result);
            if(callback){
                callback(err,result);
            }
        });
    });
}
//修改
MongoDB.prototype.update = function(data,updateData,callback){
    let dbName = this.dbName;
    let collection = this.collection;
    this.connect(this.url,function(err,db){
        if (err) throw err;
        var client = db.db(dbName);
        client.collection(collection).remove(data,updateData,function(err, result) {
            if (err) throw err;
            console.log(result);
            if(callback){
                callback(err,result);
            }
        });
    });
}
module.exports = MongoDB;

模組一如何使用

var MongoClient1 = require('mongodb').MongoClient;
var url1= "mongodb://localhost:27017/";
var dbName1 = "runoob";
var collection1 = "site2";
var oneObj = { name: "name1", url: "www.runoob" };
var myobj =  [
            { name: 'name2', url: 'https://www.baidu.com', type: 'cn'},
            { name: 'name3', url: 'https://www.google.com', type: 'en'},
            { name: 'name4', url: 'https://www.google.com', type: 'en'}
           ];

var mongodb = require("./MongoDBHandler");//引入包

var mongo = new mongodb(MongoClient1,url1,dbName1,collection1);
mongo.insertOne(oneObj,function(err,res){//插入單條
    console.log(res+ res.insertedCount);
});
mongo.insertMany(myobj,function(err,res){
    console.log(res,res.insertedCount);
});
mongo.remove({"type":"cn"},function(err,res){
    console.log(res);
})
mongo.find({},function(err,res){
    console.log(res);
});

模組二
命名為MongoDBHandler.js

function MongoDB(MongoClient,url,dbName,collection){
    //插入單條資料
    this.insertOne = function(oneObj,callback){
        MongoClient.connect(url,function(err,db){
            var client = db.db(dbName);
            client.collection(collection).insertOne(oneObj, function(err, res) {
                if (err) throw err;
                console.log("單個文件插入成功");
                if(callback){
                    callback(err,res);
                }
            });
            db.close();
        });
    }
    //批量插入
    this.insertMany = function(objs,callback){
        if(!Array.isArray(objs)){
            throw new Error("非陣列，型別不匹配!");
            return;
        }
        MongoClient.connect(url,function(err,db){
            var client = db.db(dbName);
            client.collection(collection).insertMany(objs, function(err, res) {
                if (err) throw err;
                console.log("批量文件插入成功");
                if(callback){
                    callback(err,res);
                }
            });
            db.close();
        });
    };
    //查詢指定條件下的資料
    this.find = function(whereStr,callback){
        MongoClient.connect(url,function(err,db){
            if (err) throw err;
            var client = db.db(dbName);
            client.collection(collection).find(whereStr).toArray(function(err, result) {
                if (err) throw err;
                console.log(result);
                if(callback){
                    callback(err,result);
                }
            });
            db.close();
        });
    }
    //刪除
    this.remove = function(whereStr,callback){
        MongoClient.connect(url,function(err,db){
            if (err) throw err;
            var client = db.db(dbName);
            client.collection(collection).remove(whereStr,function(err, result) {
                if (err) throw err;
                console.log(result);
                if(callback){
                    callback(err,result);
                }
            });
            db.close();
        });
    }
    //修改
    this.update = function(data,updateData,callback){
        MongoClient.connect(url,function(err,db){
            if (err) throw err;
            var client = db.db(dbName);
            client.collection(collection).remove(data,updateData,function(err, result) {
                if (err) throw err;
                console.log(result);
                if(callback){
                    callback(err,result);
                }
            });
            db.close();
        });
    }
};
module.exports = MongoDB;

使用方法同模組一