PDO - Call to a member function fetch() on a non-object? - php

Question

I looked at all the other posts on this and none of them came up with exactly what my problem is so here we go:
$dbh stores my PDO connection, if I do a var dump on it, it returns:
object(PDO)#1 (0) { }
So I know my PDO connection is working. I then use $sth to hold my query:
$c = 2;
$sth = $dbh->query("SELECT * FROM table WHERE ID = " . $c);
Then to make sure this is working I did:
echo $sth->rowCount();
That return a value of 6. So I know it is grabbing some rows. My next step of checking my problem was to fetch a single row like the following:
$row = $sth->fetch()
print_r($row);
This returned a single row (as it should) with the $row array filled exactly how I would expect it (column names as keys and column values as the array value).
So we are good up to this point. Once I move $row = $sth->fetch() into a while loop my script fails the error it returns is: Call to a member function fetch() on a non-object
Here is my while loop:
while($row = $sth->fetch()){
//while loop stuff here
}
I know it has something to do with the condition of the loop because even when I comment out all the stuff in the middle it still isn't working. What am I doing wrong? Why won't this work? I'm beyond confused on this as it has worked in the past with all the PDO I have done but for some reason it is failing in this script.
If anyone has any tips or something that can help it would be greatly appreciated.
EDIT Since ninetwozero's post worked, I'm posting my class and basically everything I've got to get this figured out.
class html_elements {
var $units;
var $useMaps;
var $cid;
var $uid;
var $companyMoney;
var $currCity;
var $terminals;
var $termLocs;
var $cityArray;
var $cargoArray;
var $cargo;
var $tid;
var $truckArray;
var $load;
var $cityID;
var $cargoID;
var $xp;
var $gasPrice;
var $warning;
function __construct($u, $maps, $c, $userID, $cMoney, $dbh, $city, $tid, $xp){
$this->units = $u;
$this->useMaps = $maps;
$this->cid = $c;
$this->uid = $userID;
$this->companyMoney = $cMoney;
$this->currCity = $city;
$this->terminals = array();
$this->termLocs = array();
$this->cityArray = array();
$this->cargoArray = array();
$this->cargo = array();
$this->tid = $tid;
$this->truckArray = array();
$this->load = 0;
$this->cityID = array();
$this->cargoID = array();
$this->xp = $xp;
$this->gasPrice = 0;
$sth = null;
$sth = $dbh->query("SELECT * FROM tblCTerminals WHERE companyID = " . $c);
//THIS LOOP FAILS
while($row = $sth->fetch()){
$this->termLocs[] = $row['Location'];
}
}
Then in another file that has my class file included in it is:
$h = new html_element($u->get_units(), $u->get_maps(), $u->get_company(), $u->get_user_id(), $c->get_money(), $dbh, $u->get_city(), $u->get_truck_id(), $u->get_xp());
Each of those getters work, I tested them. Also $dbh is what is used my connection file that is included before anything else. So I know all of that is working.

Answer 1

I got to say that you've encountered a pretty interesting error, so let's try some things to pinpoint the cause:
if( $sth == null ) die('My sth is null at #1');
while( $row = $sth->fetch() ) {
if( $row == null ) die('My row is null at #2');
echo '<pre>';
print_r($row);
echo '</pre>';
}
Let me know what this tells you.
Edit:
$sql = 'SELECT * FROM tblCTerminals WHERE companyID = ' . $c;
if( intval($c) == 0 ) { die('Aaaaaaaaaa.......aaaaah.');
foreach ($dbh->query($sql) as $row) {
echo '$row[\'Location\'] is: ' . $row['Location'] .'<br />';
$this->termLocs[] = $row['Location'];
}