SQL문질문입니다........

<?php
    $sql = "select * from item_pool_child  where item_pool_code = '".$item_pool_code."'  order by sun asc,idx asc";
    $res = sql_query($sql);
    $i=1;
    $total_item=0;
    $total_correct_item=0;
    while($row = sql_fetch_array($res)){
    $total_item++;    
    ?>
    <div class="item <?php if ($i % 2==1) echo "hol"; ?>" >

            <?php 
                $answer_ok="";
                if ($row["is_ju"]=="y" && $_POST["idx"][$i-1]==$row["idx"]  && $_POST["answer"][$i-1] &&  $_POST["answer"][$i-1]==$row["ju_answer"]){
                    $answer_ok="Y";
                    echo "<span  class='correct'></span>";
                    $total_correct_item++;
                }else if ( $_POST["idx"][$i-1]==$row["idx"]  && $_POST["answer"][$i-1] &&  $_POST["answer"][$i-1]==$row["answer"]){
                    $answer_ok="Y";
                    echo "<span  class='correct'></span>";
                    $total_correct_item++;
                }else if ($_POST["idx"][$i-1]) {
                    $answer_ok="N";
                    echo "<span class='mistake'></span>";
                }
            ?>