Roy Tutorials

In this tutorial I am going to show you how to build CRUD application using CodeIgniter 4, MySQL and React JS framework. CRUD is an acronym that stands for Create, Read, Update and Delete operations in a particular application. So you are basically creating a record, reading single or all records, updating the existing record and deleting the existing record….

Here I am going to show you an example how to encrypt PDF to make it password protected using PyPDF2 module in Python programming language. I am not going to show you how to create a new PDF file in this example and I am going to read the existing PDF file and making this PDF file password protected. It…

Image Watermark In this tutorial I am going to show you an example on how to watermark image with text using Python. You might have seen somewhere online portal or social network portals that some images are watermarked, because the owners of the images want to prevent misuse of the images. Here I am going to show you how you…

In this tutorial I am going to show you how you can build an online visitor tracking system using PHP based framework CodeIgniter 4, MySQL 8 and AJAX technique. The similar system for tracking online visitors on web site, I built in past, using CodeIgniter 3 framework. As a web site owner you would like to the progress to the…

You might encounter the following issue while executing an SQL query qith Group By clause in MySQL database server. Error Type: mysqli_sql_exception #1055 Error Details: Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column ‘roytuts.visitors.access_date’ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

Parallel Jobs In this example I am going to show you how to run multiple batch jobs parallelly in Spring Batch framework. Spring Batch is a lightweight, comprehensive batch framework designed to enable the development of robust batch applications vital for the daily operations of enterprise systems. Spring Batch provides reusable functions that are essential in processing large volumes of…

Here I am going to show an example how you can add images to word file in Python programming language. Generally you write headings, paragraphs, etc. to describe an event or something in the word file. To explain better pictorially about the same thing you need to insert or add images. python-docx is a Python library for creating and updating…

In this tutorial I am going to show you an example on deploying Spring Boot application to Heroku cloud. I will create a basic CRUD application with Spring Boot Data JPA and PostgreSQL/MySQL technologies. I will first show you how to perform CRUD operations locally, then deploy the same application in the Heroku cloud with some modifications. CRUD is an…

In this example I will show you installing PostgreSQL zip archive in Windows environment. I will show you how to setup username and password for your PostgreSQL database server. I am also going to show you some basic commands for listing all database, switching to another database, creating a new database, showing all tables, creating a new table, database backup,…

Parallel Stream Vs CompletableFuture I am going to discuss here CompletableFuture vs Parallel Stream in Java programming language. CompletableFuture extends Future with added advantage to allow the tasks finish in an ad hoc manner, whereas, in Parallel Stream task is divided into sub-tasks and run on separate threads to be completed faster. Both CompletableFuture and Parallel Stream were added in…