PDO Bind Param Trouble - php

Question

I'm trying to convert my codes to PDO from mysql_query, and starting with this function
function label_for_field($field_name, $table_name) {
$table = array();
// Bind variables to parameters
$param_array = array(':bundle' => $table_name, ':field_name' => $field_name);
// Prepare Query Statement
$query = "SELECT data FROM field_config_instance WHERE bundle = :bundle AND field_name = :field_name";
$STH = $DBH -> prepare($query);
// Execute
$STH -> execute($param_array);
// Set the fetch mode
$STH -> setFetchMode(PDO::FETCH_OBJ);
while ($row = $STH -> fetch()) {
$info = unserialize($row -> data);
$table[] = $info['label'];
}
return $table[0];
}
and I'm trying out just output it to see if it works
include_once ("includes/connect.php");
include ("includes/functions.php");
echo label_for_field("field_account_number", "account_table");
And here's the connect.php
// Include Constants
require_once ("constants.php");
//Establish Connection
try {
$DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
}
catch (PDOException $e) {
echo $e -> getMessage();
}
I don't know if it's because I'm binding the parameters wrong, it just gave me an server error page
"Server error. The website encountered an error while retrieving ......."
Thanks in advance

Answer 1

You need to set the PDO error mode to produce exceptions before you can catch them.
In your connect.php:
try {
$DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
$DBH->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
Then you can have a similar try/catch statement in your function to that of your connection file, and use it to show the error in your development environment.

Answer 2

Try this instead to see if you get valid objects returned from the query.
// Prepare Query Statement
$query = "SELECT data FROM field_config_instance WHERE bundle = :bundle AND field_name = :field_name";
$STH = $DBH -> prepare($query);
$STH->bindValue(":bundle", $table_name);
$STH->bindValue(":field_name", $field_name);
$STH->execute();
$STH->setFetchMode (PDO::FETCH_OBJ);
$result = $STH->fetchAll();
var_dump($result);