SQL injection is a serious concern for developers, and there are a number of ways of dealing with it; however the best, and most proven method, is through parameter binding. What parameter binding does is substitute variable data within a query with parameters, which are then replaced by the database driver during query execution. Since the database driver is intimately aware of which parts of the query are parameters it can parse the query and then execute it with the bound parameters safely set.

The framework that Blesta 3 is built on, minPHP, handles parameter binding through use of the PDO extension. But because writing queries is tedious and prone to typos, minPHP offers a database access object to interface with PDO in the Record class. A query that would otherwise looks like this…

$this->query("SELECT `users`.`first_name`, `users`.`last_name` FROM `users` WHERE `id`=?", 3);

becomes…

$this->Record->select(array("users.first_name","users.last_name"))->from("users")->where("id", "=", 3);

No need to worry about syntax, semantics, escaping data, or back-ticks. That’s all handled by the computer, which loves performing tedious operations over and over.

We’ll look at how to overcome cross site scripting (XSS) vulnerabilities next week.