PDO::fetchAll not working with MySQL stored procedure - php

Question

I'm trying to return a row from a database by calling a stored procedure throught PHP. However, when I do this how I normally would I get a "General Error".
Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error in C:\xampp\htdocs\Skilaverkefni 4\Courses\read.php:11
Stack trace:
#0 C:\xampp\htdocs\Skilaverkefni 4\Courses\read.php(11): PDOStatement->fetchAll(2)
#1 C:\xampp\htdocs\Skilaverkefni 4\index.php(13): ReadCourse('FOR3L3U')
#2 {main}
thrown in C:\xampp\htdocs\Skilaverkefni 4\Courses\read.php on line 11
Here is the code:
<?php
function ReadCourse($courseID)
{
require "dbCon.php";
$SQL = "SET #p0='" . $courseID . "'; CALL ReadCourse(#p0);";
echo "$SQL";
$logon = $pdo->prepare($SQL);
$logon->execute();
$records = $logon->fetchAll(PDO::FETCH_ASSOC);
print_r($records);
}
?>
After a long Google-session I found out that the issue is most caused by the way I'm handling the reading of the data returned from the stored procedure, how do I do this correctly?

Answer 1

The whole point of PDO is to make it impossible to run any old database query you choose to pass as a string.
From the documentation:
<?php
/* Call a stored procedure with an INOUT parameter */
$colour = 'red';
$sth = $dbh->prepare('CALL puree_fruit(?)');
$sth->bindParam(1, $colour, PDO::PARAM_STR|PDO::PARAM_INPUT_OUTPUT, 12);
$sth->execute();
print("After pureeing fruit, the colour is: $colour");
?>