php选项值链接

Question

我创建了一个下拉菜单，当单击下拉栏中类别的选项时，它可以链接到我的产品页面，但我无法链接它们，有人知道我的代码有什么问题吗？

在此处输入代码

$link=mysql_connect("localhost","root","")or die("Can't Connect...");
mysql_select_db("fyp",$link) or die("Can't Connect to Database...");
$query="select * from category ";
$res=mysql_query($query,$link);

while($row=mysql_fetch_assoc($res))
{
    echo "<option value='product.php category=".$roww['$cat_id']."'>".$row['cat_nm'];///here is the problem
    $qq = "select * from subcat where parent_id=".$row['cat_id'];
    $ress = mysql_query($qq,$link) or die("wrong delete subcat query..");
    while($roww = mysql_fetch_assoc($ress))
    {
        echo "<option value='".$roww['subcat_id']."'> ---> ".$roww['subcat_nm'];//here is the problems
    }

}

mysql_close($link);

?>

enter image description here

Answer 1

尝试这个并使用 mysqli 而不是 mysql，mysql 已弃用(建议)

    $link=mysqli_connect("localhost","root","")or die("Can't Connect...");
    mysqli_select_db($link,"fyp") or die("Can't Connect to Database...");
    $query="select * from category";
    <select onselect='goUrl(this.value)' id="cval" name="cval">
    $res=mysqli_query($link,$query);

    while($row=mysqli_fetch_assoc($res))
    {
       echo "<option value='".$row['cat_id']."'>".$row['maincatname']."</option>";
        $qq = "select * from subcat where parent_id=".$row['cat_id'];
        $ress = mysqli_query($link,$qq) or die("wrong delete subcat query..".mysqli_error($link));
        while($roww = mysql_fetch_assoc($ress))
        {
            echo "----><option value='".$roww['subcat']."'>".$roww['subcatname']."</option>";
        }
    }
    </select>

    mysqli_close($link);

    ?>
    <script>
    function goUrl(catgry)
    {
    window.location.href='product.php?category='+catgry;
    }
    </script>