How can I prevent SQL injection in PHP?

There are several ways to prevent SQL injection attacks in PHP:

  1. Use prepared statements and parameterized queries: These are SQL statements that are sent to the database separately from any parameters. This helps to prevent attackers from injecting malicious code into your SQL statement.

  2. Use stored procedures: Stored procedures are pre-compiled SQL statements that are stored in the database. They can accept input parameters and return multiple result sets. Using stored procedures can help to reduce the risk of SQL injection attacks.

  3. Validate user input: Make sure to validate all user input to ensure that it is safe and does not contain any malicious code. This can be done using functions such as mysqli_real_escape_string() or PDO::quote().

  4. Use an escaping function: You can use a function like htmlspecialchars() or htmlentities() to escape any special characters in user input. This will help to prevent attackers from injecting malicious HTML or JavaScript code into your web application.

  5. Use an ORM (Object-Relational Mapper): ORMs such as Doctrine or Eloquent can help to prevent SQL injection attacks by automatically escaping user input and using prepared statements.

  6. Use a web application firewall: A web application firewall (WAF) can help to protect your application from SQL injection attacks by monitoring and blocking suspicious traffic.

By following these best practices, you can significantly reduce the risk of SQL injection attacks in your PHP application.