Git is a distributed version control system DVCS designed for efficient source code management, suitable for both small and large projects. It allows multiple developers to work on a project simultaneously without overwriting changes, supporting collaborative work, continuous integration, and deployment. This Git and GitHub tutorial is designed for beginners to learn fundamentals and advanced concepts, including branching, pushing, merging conflicts, and essential Git commands. Prerequisites include familiarity with the command line interface CLI, a text editor, and basic programming concepts. Git was developed by Linus Torvalds for Linux kernel development and tracks changes, manages versions, and enables collaboration among developers. It provides a complete backup of project history in a repository. GitHub is a hosting service for Git repositories, facilitating project access, collaboration, and version control. The tutorial covers topics such as Git installation, repository creation, Git Bash usage, managing branches, resolving conflicts, and working with platforms like Bitbucket and GitHub. The text is a comprehensive guide to using Git and GitHub, covering a wide range of topics. It includes instructions on working directories, using submodules, writing good commit messages, deleting local repositories, and understanding Git workflows like Git Flow versus GitHub Flow. There are sections on packfiles, garbage collection, and the differences between concepts like HEAD, working tree, and index. Installation instructions for Git across various platforms Ubuntu, macOS, Windows, Raspberry Pi, Termux, etc. are provided, along with credential setup. The guide explains essential Git commands, their usage, and advanced topics like debugging, merging, rebasing, patch operations, hooks, subtree, filtering commit history, and handling merge conflicts. It also covers managing branches, syncing forks, searching errors, and differences between various Git operations e.g., push origin vs. push origin master, merging vs. rebasing. The text provides a comprehensive guide on using Git and GitHub. It covers creating repositories, adding code of conduct, forking and cloning projects, and adding various media files to a repository. The text explains how to push projects, handle authentication issues, solve common Git problems, and manage repositories. It discusses using different IDEs like VSCode, Android Studio, and PyCharm, for Git operations, including creating branches and pull requests. Additionally, it details deploying applications to platforms like Heroku and Firebase, publishing static websites on GitHub Pages, and collaborating on GitHub. Other topics include the use of Git with R and Eclipse, configuring OAuth apps, generating personal access tokens, and setting up GitLab repositories. The text covers various topics related to Git, GitHub, and other version control systems Key Pointers Git is a distributed version control system DVCS for source code management. Supports collaboration, continuous integration, and deployment. Suitable for both small and large projects. Developed by Linus Torvalds for Linux kernel development. Tracks changes, manages versions, and provides complete project history. GitHub is a hosting service for Git repositories. Tutorial covers Git and GitHub fundamentals and advanced concepts. Includes instructions on installation, repository creation, and Git Bash usage. Explains managing branches, resolving conflicts, and using platforms like Bitbucket and GitHub. Covers working directories, submodules, commit messages, and Git workflows. Details packfiles, garbage collection, and Git concepts HEAD, working tree, index. Provides Git installation instructions for various platforms. Explains essential Git commands and advanced topics debugging, merging, rebasing. Covers branch management, syncing forks, and differences between Git operations. Discusses using different IDEs for Git operations and deploying applications. Details using Git with R, Eclipse, and setting up GitLab repositories. Explains CI/CD processes and using GitHub Actions. Covers internal workings of Git and its decentralized model. Highlights differences between Git version control system and GitHub hosting platform.
Hello Friends, In this tutorial we will learn how to prevent SQL injection in PHP using PDO prepared statements. Here's an example code snippet to demonstrate how to do so:
Step 1: Create a PDO connection
First, you need to establish a connection to your database using PDO. Here's an example:
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
try {
$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
echo "Connected successfully";
} catch(PDOException $e) {
echo "Connection failed: " . $e->getMessage();
}
?>
Step 2: Use prepared statements
Instead of concatenating user input directly into your SQL queries, you should use prepared statements. Prepared statements separate the SQL statement from the user input, which prevents SQL injection attacks. Here's an example:
<?php
$stmt = $conn->prepare("SELECT * FROM users WHERE username = :username AND password = :password");
$stmt->bindParam(':username', $username);
$stmt->bindParam(':password', $password);
// execute the query
$stmt->execute();
?>
In the above example, the user input is bound to the prepared statement using the bindParam() function. The :username and :password placeholders in the SQL statement are replaced with the actual user input at runtime.
Step 3: Sanitize user input
Even though prepared statements prevent SQL injection attacks, it's still a good practice to sanitize user input. Sanitization is the process of removing any unwanted characters or formatting from user input. Here's an example of how to sanitize user input:
<?php
// sanitize user input
$username = filter_var($_POST['username'], FILTER_SANITIZE_STRING);
$password = filter_var($_POST['password'], FILTER_SANITIZE_STRING);
?>
In the above example, we use the filter_var() function with the FILTER_SANITIZE_STRING flag to remove any unwanted characters or formatting from the $_POST variables.
Step 4: Use parameterized queries
Another way to prevent SQL injection attacks is to use parameterized queries. Parameterized queries use placeholders in the SQL statement, which are then replaced with actual values at runtime. Here's an example of how to use parameterized queries:
<?php
$stmt = $conn->prepare("SELECT * FROM users WHERE username = ? AND password = ?");
$stmt->bindParam(1, $username);
$stmt->bindParam(2, $password);
// execute the query
$stmt->execute();
?>
In the above example, we use the ? placeholder in the SQL statement, and the bindParam() function to bind the user input to the prepared statement.
Step 5: Use input validation
In addition to sanitizing user input, you should also validate user input to ensure it meets your application's requirements. Input validation is the process of checking if the user input is valid, such as checking if it's the correct data type or if it meets a certain length requirement. Here's an example of how to use input validation:
<?php
// validate user input
if (!isset($_POST['username']) || !is_string($_POST['username']) || strlen($_POST['username']) > 50) {
die('Invalid username');
}
if (!isset($_POST['password']) || !is_string($_POST['password']) || strlen($_POST['password']) > 50) {
die('Invalid password');
}
// sanitize
