Add Charts to Your Android App Using MPAndroidChart

If your app deals with a lot of data, using charts instead of tables to display that data could lead to a vastly better user experience. In this tutorial, you are going to learn about a popular open source charting library MPAndroidChart. The charts of this library are highly customizable, interactive, and easy to create.

source :–cms-23335

RESTful API Using Node and Express 4

In this tutorial we’ll learn how to create basic REST API’s using Node.js and Express which retrieve data from MySQL database and give response in JSON format.

This tutorial is for the beginners and intermediate users of Node.js.


source :

Illegal mix of collations MySQL Error

I’m getting this strange error while processing a large number of data…

Error Number: 1267

Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '='

SELECT COUNT(*) as num from keywords WHERE campaignId='12' AND LCASE(keyword)='hello again 昔 ã‹ã‚‰ ã‚ã‚‹ å ´æ‰€'

Solusi : 

SET collation_connection = 'utf8_general_ci'

then for your databases



MySQL sneaks swedish in there sometimes for no sensible reason.

How to create an nodejs https server?

To create an HTTPS server, you need two things: an SSL certificate, and Node’s built-in https module.

We need to start out with a word about SSL certificates. Speaking generally, there are two kinds of certificates: those signed by a ‘Certificate Authority’, or CA, and ‘self-signed certificates’. A Certificate Authority is a trusted source for an SSL certificate, and using a certificate from a CA allows your users to be trust the identity of your website. In most cases, you would want to use a CA-signed certificate in a production environment – for testing purposes, however, a self-signed certicate will do just fine.

To generate a self-signed certificate, run the following in your shell:

Android Menus and Popups


Apps often need to provide the user with a consistent experience for executing actions that are contextually specific. The most common actions for an activity live on the default Action Bar but actions that are more specific to an item or element can be displayed contextually using menus and popups. In addition to menus, apps often need to display popup overlays that contain informational content. This guide covers how to manage menus and popups within your Android apps.