how to suppress foreach() warnings php
===

I need help suppressing a warning that I am getting from a `foreach()`

    Warning: Invalid argument supplied for foreach() in 
    /sitename/pages/admin/questions/index.php
I am getting the result I want. All I need is to remove the warning... 

This is my code:

    for($i = 1; $i <= $RESULTS_count; $i++){

	$rawResult = $wpdb->get_row(
					$wpdb->prepare("SELECT * FROM ".WPSQT_TABLE_RESULTS." WHERE id = $i"),ARRAY_A);
									
	$rawResult['sections'] = unserialize($rawResult['sections']);
		
	     foreach($rawResult['sections'] as $result_sections){
		     if($result_sections['answers'][1]['mark'] == 'correct') $correct_answer++;
		}
    }
    echo $correct_answer/$RESULTS_count;

What do you think I should do?