PHP PDO: Call to a member function prepare() & list? - php

Question

Fatal error: Call to a member function prepare() on a non-object
Is what I am getting when I try to do:
$sql = $connect->prepare ("SELECT id, pwd, firstname, lastname, approved, user_level FROM users WHERE $user_cond AND banned = 0"); // SELECT
$sql->execute ();
$sql->setFetchMode(PDO::FETCH_ASSOC);
$num = $connect->rowCount();
Im holding on rewriting my system, taking out all mysql_* and make use of pdo instead.
This is what was before:
$result = mysql_query("SELECT `id`,`pwd`,`firstname`,`lastname`,`approved`,`user_level` FROM users WHERE
$user_cond
AND `banned` = '0'
") or die (mysql_error());
$num = mysql_num_rows($result);
What have I done wrong?
And with list() I have:
list($id,$pwd,$firstname,$lastname,$approved,$user_level) = mysql_fetch_row($result);
instead of mysql_fetch_row($result); what should I do in PDO?
My PDO object/connection:
try{
$connect = new PDO("mysql:host=".DB_HOST.";dbname=".DB_NAME.";charset:UTF-8", DB_USER, DB_PASS, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
}
catch(PDOException $pe)
{
die('Could connect to the database because: ' .$pe->getMessage());
}

Answer 1

Fatal error: Call to a member function
prepare() on a non-object
usually means that something failed and your variable is not what you expect it to be. $connection is probably false.
PDOStatement::fetch
list($id,$pwd,$firstname,$lastname,$approved,$user_level) = $sql->fetch();
Also call rowCount on the statement, not on the connection:
$sql->rowCount();

Answer 2

Since you using prepare, you should make the $cond a named parameter and then do this:
in this example the condition is just user_id, but you can have multiple conditions and multiple named parameters, just bind() each one the same way
$sth = $pdo->prepare ("SELECT id, pwd, firstname, lastname, approved, user_level FROM users WHERE user_id = :cond AND banned = 0");
$sth->bindParam(':cond', $some_user_id);
$sth->execute ();
$a = $sth->fetch( PDO::FETCH_ASSOC );
The $a will be your assiciate array, print_r($a) to see what's in it

Answer 3

Looks like a scope issue.
Are you assigning $connect within a function, class, namespace or are you running prepare in a function, class or namespace ?
if your assigning $connect within a function then that function should return the PDO Connection. I would introduce a static instance like so:
class Database extends PDO
{
private $instance = null;
public static function Instance()
{
if(self::$instance == null)
{
self::$instance = new Database();
}
return self::$instance;
}
private function __construct(){}
private function __connect()
{
try
{
parent::__construct("mysql:host=".DB_HOST.";dbname=".DB_NAME.";charset:UTF-8", DB_USER, DB_PASS, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION))
}catch(PDOException $e)
{
die($e->getMessage());
}
}
}
then use like so:
$Database = Database::Instnace();
$Database->prepare("...");

Answer 4

The error is most likely due to the MySQL connection failing - therefor $connect is not a valid PDO object - so as the error says, you're trying to call a method on an object which doesn't support it. What does your connection handling code look like? Did you check if a connection was successfully created?