I'm building a PHP application with PDO or MySQLi and want to handle database queries securely. Are prepared statements with bound parameters the best practice for preventing SQL injection, or should I combine them with other security measures such as input validation, restricted database permissions, or an ORM?
3 Answers
Never rely on browser-side checks or JavaScript validation for security. A client can send any request directly, so validation must happen on the server. For values that cannot be bound as normal parameters—such as a sort column, table name, or SQL keyword—use a strict allowlist of permitted values instead of inserting arbitrary input into the query.
Use defense in depth as well. Give the application a dedicated database account with only the permissions it needs, never use the database administrator account, and validate input according to the field’s expected type and format. Validation helps reject bad data, but it does not replace parameterized queries because valid-looking input can still be malicious.
Yes—prepared statements with bound parameters should be your primary defense. They keep user data separate from the SQL code, so input cannot change the structure of the query. This applies to both PDO and MySQLi. Avoid concatenating or interpolating user input into SQL. An ORM such as Doctrine or Eloquent can make database work easier, but it is only safe when you use its parameterized APIs rather than constructing raw SQL unsafely.
That clears it up—thank you. I’ll focus on learning prepared statements properly rather than building queries with string concatenation.
Also avoid displaying raw PDO or MySQLi errors to users. Log detailed exceptions on the server, but return a generic error message so table names, columns, and query details are not exposed.