Prepared Request and PDO in PHP

Introduction

When building applications with PHP, database interactions are often required. To access databases, we use database APIs such as PDO. With PDO, we can prepare SQL statements, preventing potential SQL injection attacks. This is where prepared requests come into play.

The Basics of Prepared Requests

Prepared requests are SQL statements that are precompiled and saved for future use. PDO prepares the SQL statement, binds parameters (sanitizing user input), and executes the statement without modifying user input. This is crucial in preventing SQL injection attacks. Prepared requests also improve performance by reducing the number of requests sent to the database.

How to Use Prepared Requests and PDO

To start using prepared requests and PDO, we first need to create a PDO connection to our database. Below is an example of how to create a PDO connection:

$pdo = new PDO('mysql:host=localhost;dbname=mydatabase', 'username', 'password');

After creating the connection, we can prepare an SQL statement and execute it. Below is an example of how to prepare an SQL statement:

$stmt = $pdo->prepare('SELECT * FROM users WHERE id = :id');
$stmt->bindParam(':id', $id, PDO::PARAM_INT);

In this example, we prepare a SELECT statement that selects all columns from the users table where the id is equal to a parameter we define (:id). We then bind the parameter to a variable $id, and specify that the parameter is an integer.

We can then execute the statement, and fetch the results:

$stmt->execute();
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);

The execute method executes the prepared statement, and fetchAll retrieves all rows returned by the statement.

Conclusion

Prepared requests prevent SQL injection attacks and improve performance by reducing the number of requests sent to the database. They are simple to use with PDO, and can enhance the security and performance of your PHP applications.