node to MONGODB implementation of additions and deletions, paging function

An increase in the content of the previous article:

node. JS Environment for MONGODB implementation Check, plug, paging function

It was originally written, but then there is a bug, do not know where the problem, yesterday only found Updatemany function to pass the argument when the CollectionName, idiot a day. Eh =-=

//Limit,skip Efficient PracticesvarExpress = Require ("Express");varApp =Express ();vardb = require ("./model/db3.js"); App.get ("/",function(req,res) {Db.insertone ("Teacher", {"name": "Little Red"},function(err,result) {if(Err) {Console.log ("Insert Failed"); } res.send ("Insert Succeeded"); });}); App.get ("/du",function(req, res) {//This page now accepts a page parameter.     varpage = parseint (req.query.page);//It's easy to read the get parameters in Express    //Find 4 parameters, in which set to check, what to check, paging setup, after checking what to do    //10 per page, check the third page    //db.find ("student", {},{"Pageamount": 5, "page":p age},function (err,result) {    //db.find ("student", {},function (err,result) {    //Note that this result is still 5, is the first find in the result set of age greater than 50, skip and limitDb.find ("Student", {"age": {$gt: 50}},{' Pageamount ": 5," page ":p Age},function(err,result) {if(Err) {Console.log (err);    } res.send (Result); });}); App.get ("/shan",function(req,res) {//note Here is the string    varrestaurant_id =req.query.id; Db.deletemany ("Teacher", {"name": "Little Red"},function(err,result) {if(Err) {Console.log (err);    } res.send (Result); });}); App.get ("/xiugai",function(req,res) {//note Here is the stringDb.updatemany ("Student", {name:haha}, {$set: {name:Hee Hee}        },        function(err,result) {if(Err) {Console.log (err); Db.close ();//Close the database} res.send (Result); });}); App.listen (3000);

//after optimization, add the Skip,limit parameter to the wording//This module encapsulates all the common operations on the database .varSettings = require (".. /settings.js ");varMongoclient = require (' MongoDB '). mongoclient;//regardless of the database operation, are connected to the database first, so we can connect the database//encapsulation becomes functionfunction_connectdb (callback) {varURL =Settings.dburl; Mongoclient.connect (URL,function(err,db) {if(Err) {callback (Err,NULL); return;    } callback (ERR,DB); });} Exports.insertone=function(CollectionName, JSON, callback) {_connectdb (function(err,db) {if(Err) {callback (Err,NULL); return; } db.collection (CollectionName). Insertone (JSON,function(err, result) {callback (err, result); Db.close ();//Close the database            })        });} Exports.find=function(collectionname,json,c,d) {varresult = [];//result Array    //JS has no function overloads, only manual implementation    if(Arguments.length = = 3) {       //if the args are not passed        //then the parameter C is callback, and parameter d is not passed.         varcallback =C; varSkipnumber = 0; //number limit, limit (0) is no limit        varLimit = 0; }Else if(Arguments.length = = 4) {        varargs =C; varcallback =D; //number of bars that should be omitted        varSkipnumber = Args.pageamount *Args.page; //Number Limit        varLimit =Args.pageamount; }Else {        Throw NewError ("The number of arguments to the Find function must be 3, or 4"); return; }    //start from page 0thConsole.log ("Skip" +skipnumber+ "bar" + "limit to" +limit+ "bar"); //link Database, link to find all_connectdb (function(err,db) {varcursor =db.collection (CollectionName). Find (JSON). Skip (Skipnumber). Limit; Cursor.each (function(err, doc) {if(Err) {callback (Err,NULL);                Db.close (); return; }           if(Doc! =NULL) {Result.push (doc);//put into the result array}Else {               //Traverse End, no more documentsCallbackNULL, result); Db.close ();//Close the database           }        }); });} Exports.deletemany=function(collectionname,json,callback) {_connectdb (function(err, db) {//Deletedb.collection (CollectionName). Deletemany (JSON,function(err, results) {callback (err, results);            Db.close ();    }        ); });} Exports.updatemany=function(collectionname,json1,json2,callback) {_connectdb (function(err,db) {db.collection (CollectionName). Updatemany (Json1, Json2,function(Err,results) {callback (err,results); Db.close ();//Close the database            }); });};

node to MONGODB implementation of additions and deletions, paging function