gistfile1.js

//npm install --save bluebird

var Promise = require('bluebird');

Check.updataPartly = function(foodName, partly, numBig, numSamll, callback){
    //打開資料庫
    mongodb.open(function(err,db){
        if (err) {
            return callback(err);
        }
        //讀取checks的集合
        db.collection('checks',function(err,collection){
            if (err) {
                mongodb.close();
                return callback(err);
            }
            
            //蒐集非同步處理工作
            var tasks = [];
            
            var task = function(i) {
                return new Promise(function(resolve, reject) {
                    collection.update({
                        "foodName":foodName[i]
                    },{//修改
                        $set: {partly: partly-(numSamll[i]+numBig[i])}
                    },function(err) {
                        mongodb.close();
                        if (err) {
                            return reject(err);
                        }
                        resolve(null);
                    });
                });
            }
            
            for (var i = 0; i < foodName.length; i++) {
                tasks.push(task(i));
            }
            
            Promise.all(tasks).then(function() {
                callback(null);
            }, function(err) {
                callback(err);
            });
        });
    });
};