PHP从所选的多个选择选项中获取数据库中的多个值

I am trying to get the multiple selected values in multiple select options from database. I am getting the result but its repeating in multiple select box. Any help is much appreciated. Thank you. Here is my Code :

<?php

    $query = "select pf_no,name from programmer order by name";
    $results=mysqli_query($con, $query); 
    if (mysqli_num_rows($results)>=0) 
    {
        while($row=mysqli_fetch_array($results))
        {
            $main_query="select p.name from programmer p,transaction t  where p.pf_no = t.pf_id  and t.owner = '0' and t.project_id = '$pr_id' group by p.name";
            $main_results=mysqli_query($con, $main_query);
            if (mysqli_num_rows($main_results)>=0) 
            {
                while($row1=mysqli_fetch_array($main_results))
                {
?>
                <option value="<?php echo $row['pf_no']; ?>"<?php if($row1['name']==$row['name']) {echo 'selected="selected"';} ?>><?php echo $row['name']; ?></option>
<?php

                }
            }
        }
    }