SQL injection attack prevention guide in PHP functions

PHP function protect_sql_injection() is used to prevent SQL injection attacks by following the following steps: Escape special characters. Convert non-ASCII characters to HTML entities. This ensures that user-supplied input is securely processed before executing database queries, preventing malicious SQL code injection.

PHP function prevent_sql_injection(): Prevent SQL injection attacks

Overview

SQL injection attacks are a serious cybersecurity vulnerability that allow attackers to manipulate databases by injecting malicious SQL code into applications. In PHP, you can optionally use the protect_sql_injection function to prevent this type of attack.

Syntax

string protect_sql_injection(string $string):string;

Function

##protect_sql_injection() The function prevents SQL injection attacks through the following steps :

Escape special characters (such as single quotes (') and double quotes (")).
1. Convert any non-ASCII characters in the string to HTML entities.

Usage

To use the

protect_sql_injection() function, simply apply it to any string containing user-supplied input. For example:

$username = protect_sql_injection($_POST['username']);
$password = protect_sql_injection($_POST['password']);

$query = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";

Practical case

Secure query execution

In a PHP application that needs to execute a database query, you can Use the

protect_sql_injection() function to prevent SQL injection. For example:

function get_user_by_username($username) {
  $username = protect_sql_injection($username);

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

  $result = mysqli_query($link, $query);
  if (!$result) {
    throw new Exception('Error executing query: ' . mysqli_error($link));
  }

  return mysqli_fetch_assoc($result);
}

Form data validation

In PHP applications that handle user input, You can use the

protect_sql_injection() function to validate data and prevent SQL injection. For example:

if (isset($_POST['username']) && isset($_POST['password'])) {
  $username = protect_sql_injection($_POST['username']);
  $password = protect_sql_injection($_POST['password']);

  // 在这里验证用户名和密码并采取适当的操作
}

.

The above is the detailed content of SQL injection attack prevention guide in PHP functions. For more information, please follow other related articles on the PHP Chinese website!