mysqli fetch_object() on non-object issue

[dragon_sa]

I am getting an error when the clear banned ip over 15mins script runs if there is a row to remove from the database, what am I doing wrong here

 

and the error is

 

PHP Fatal error:  Call to a member function fetch_object() on a non-object in /path/to/file/index.php on line 14

 

<?php 
// clear banned ip over 15mins
$timeBAN = time();
$sql = $link->query("SELECT unban, id FROM attempts WHERE unban <= '$timeBAN'");
if ($sql->num_rows > 0) {
	while ($result = $sql->fetch_object()) { //<----THIS IS LINE 14 CAUSING ERROR if there is data
		$remove=$result->id;
		$sql = $link->query("DELETE FROM attempts WHERE id='$remove'");
	}
	$sql->close();
}
// check if user banned
$sql = $link->query("SELECT ip, unban FROM attempts WHERE ip='$ip'");
if ($sql->num_rows > 0) {
	$result = $sql->fetch_object();
	$unban = $result->unban;
	$timeCHECK = $unban-$timeBAN;
	if ($timeCHECK > 0 ) {
		$remain = round($timeCHECK/60);
	}
	$sql->close();
}
// reset the auto_increment of attempts
$sql = $link->query("SELECT id FROM attempts");
if ($sql->num_rows == 0) {
	$sql = $link->query("ALTER TABLE attempts AUTO_INCREMENT = 1");
}
?>

[PFMaBiSmAd]

You are overwriting the $sql variable inside the while(){} loop, so the second time through the loop it no longer contains the result object from the SELECT query.

[dragon_sa]

Doh!! bit of an oversight I am just converting from my mysql ways to mysqli so still getting use to it