How to use prepared statements in PHP to prevent SQL injection attacks?

The use of prepared statements in PHP can effectively defend against SQL injection attacks. Prepared statements prevent attackers from inserting malicious strings by allowing query parameters to be defined before the query is executed. It offers greater security, better performance, and ease of use.

Use prepared statements in PHP to defend against SQL injection attacks

What is a SQL injection attack?

SQL injection is an attack technique in which an attacker controls database queries through malicious strings to gain unauthorized access or perform harmful operations.

How to use prepared statements to prevent SQL injection?

A prepared statement is a database query that allows you to define query parameters before executing the query. This way, attackers are prevented from inserting malicious strings into queries.

Practical case

Create a PHP script to simply query user data:

$username = $_GET['username'];
$query = "SELECT * FROM users WHERE username = '$username'";

Use mysqli_prepare(), mysqli_bind_param() and mysqli_stmt_execute() to create and execute a preprocessed query:

$stmt = mysqli_prepare($conn, $query);
mysqli_stmt_bind_param($stmt, "s", $username);
mysqli_stmt_execute($stmt);

In this example, sspecifies that the parameter is a String.

Advantages

• Higher security: Prepared statements enhance security by preventing attackers from manipulating queries.
• Better performance: Prepared statements cache the query on the server, thus improving performance because it does not require compiling the same query multiple times.
• Easy to use: Prepared statements are easy to use and the syntax is simple and easy to understand.

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