MySQL准备语句(两个表的数据)和PHP & for循环组合

Question

我在MySQL中有两个表，使用mysqli准备语句。

MySQL表：

Menu_table

menuID (PK)    - menuName
    1             Menu 1
    2             Menu 2
    3             Menu 3
    4             Menu 4

Submenu_table

 submenuID(PK) -   submenuName   - menuID
    1               submenu 1     1
    2               submenu 2     1
    3               submenu 1     4
    4               submenu 2     4 

我的死锁是在遍历时间或嵌套循环时，为子菜单和菜单传递正确的值。

PHP代码(使用WHILE循环，稍后使用FOR循环和合并)：

<ul class="top-bar">
<?php
while($row = $stmt1->fetch()){
?>

            <li>
                <a href=""><span><?php echo($menuName);?></span></a>
                <?php 
                while($row = $stmt2->fetch()){
                    ?>
                    <ul class="sub"><li><?php echo($submenuName);?></li></ul>
                    <?php
                }
                ?>
            </li>
        <?php
}
?>
</ul>

for($i=0; $i<$stmt1->num_rows;$i++){
    //write Menu Item
    //New loop through submenu
    //how to get index of Menu as reference point for submenu for loop
}

预期结果：

<ul class="top-bar">
    <li>
        <a href=""><span>Menu 1</span></a>
        <ul class="sub"><li>Submenu 1-1</li></ul>
        <ul class="sub"><li>Submenu 1-2</li></ul>
    </li>

    <li>
        <a href=""><span>Menu 2</span></a>
    </li>

    <li>
        <a href=""><span>Menu 3</span></a>
    </li>

    <li>
        <a href=""><span>Menu 4</span></a>
        <ul class="sub"><li>Submenu 4-1</li></ul>
        <ul class="sub"><li>Submenu 4-2</li></ul>
    </li>
</ul>

Answer 1

<ul class="top-bar">
<?php
while($row = $stmt1->fetch()){
?>

            <li>
                <a href=""><span><?php echo($menuName);?></span></a>
                <?php 
     $sql = "select * from submenu_table where menuID = ".$row['menuID'];
$stmt2->query($sql);
                while($sub_row = $stmt2->fetch()){
                    ?>
                    <ul class="sub"><li><?php echo($sub_row['submenuname']);?></li></ul>
                    <?php
                }
                ?>
            </li>
        <?php
}
?>
</ul>