MySQL, Database CRUD, PDO, mysqli, and Prepared Statements
Connect PHP to relational databases safely and learn how CRUD operations work in real data-driven applications.
Inside this chapter
- Why Databases Matter
- Connecting with PDO
- CRUD Example
- Prepared Statements and Security
- Business Example
Series navigation
Study the chapters in order for the clearest path from PHP basics to backend architecture, security, deployment, and production engineering habits. Use the navigation at the bottom to move smoothly through the full tutorial series.
Why Databases Matter
Most PHP applications are data-driven. They store users, products, orders, submissions, reports, permissions, and application history in databases. Learning PHP without database access leaves out a major part of real backend development.
Connecting with PDO
$pdo = new PDO("mysql:host=localhost;dbname=learning", "root", "");
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);PDO provides a flexible, consistent interface for database access. Many teams prefer it for portability and clean prepared-statement support. Existing projects may also use mysqli, which is still common and valid.
CRUD Example
$stmt = $pdo->prepare("INSERT INTO students (name, email) VALUES (?, ?)");
$stmt->execute(array($name, $email));Create, read, update, and delete operations are at the heart of admin panels, registration systems, content managers, and reporting tools.
Prepared Statements and Security
Prepared statements help prevent SQL injection by separating SQL structure from user-supplied values. This is one of the most important backend security habits developers must learn.
Business Example
A school management system may store student records, attendance data, class schedules, and fee payments in MySQL. PHP acts as the layer that validates requests, performs SQL operations, and returns user-facing responses.