title: Protect get variable from SQL injection with PHP isnumeric function
body: <p>I have a PHP script that depending on the value of an id in a GET variable will retrieve different data from a mysql database. The value of the id should be a number at all times. Instead of changing my current mysql query to use PDO, would running isnumeric on the Get variable and exiting the script if it is not a number be sufficient to protect against injection in all or most cases, ie, would it still be possible for some injection sql to slip through isnumeric? </p>
  
  <p>Just a humble comment on the duplicate question issue, I looked at the suggested duplicate question and think that as a beginner it might not be clear on its face that my question is an exact duplicate of that one.</p>