Question

I am attempting to get the following PDO statement to work and running into issues. When I am trying to get the number of rows, I keep getting 0, yet I know there should be 1 row. When I ran it as a mysqli statement( before trying to change it to PDO) it worked perfectly.
Here is the code:

    require_once ('pdo.php');
$isbn = $_POST['isbn'];
    // check to see if the isbn is a "problem" isbn or not
$problem = $conn->prepare("select isbn, note from problem where isbn = :isbn");
$problem->bindParam(":isbn", $isbn);
$problem->execute();
print_r($problem);

$num_rows = $problem->rowCount();

print_r($num_rows); die;

EDIT: Here is pdo.php:

    <?php

function db_connect()
{ 
$db = new PDO("mysql:host=localhost; db=bookcell_BCOS_final", "xxxxx", "xxxxx");
return($db);
}
?>

I know that my connection works, but I get 0 for $num_rows. What mistakes am I making here?

Answer 1

Besides a little quirk and a optimalisation your code looks fine to me. The posted value isbn could be the reasong that you are getting no data:

$problem = $conn->prepare("select isbn, note from problem where isbn = :isbn"); 
$problem->bindParam(":isbn", $_POST['isbn'], PDO::PARAM_STR); // <-- thats what parameter binding is for 
$problem->execute(); 
print_r($problem); 

$num_rows = $problem->rowCount(); // <-- gives the number of rows, not columnCOunt 

print_r($num_rows); die;