Question

我想从MySQL数据库创建菜单树。下面是我的PHP代码。我无法从数据库中获取数据。我已经显示了显示我当前的PHP代码的数据。我还展示了实际的数据库数据。

如何显示菜单树？

<?php require_once 'include/dbpdo.php'; ?>
<html>
<head>
<style>


</style>
</head>
<body>
<?php
$stmt = $pdo->query('SELECT * FROM `category` where `parent_id` = 0');
$stmt->execute();
?>
<ul>
    <?php while($menu1 = $stmt->fetch()){ ?>
        <li><a href="<?php echo $menu1['category_link'] . "\n"; ?>"><?php echo $menu1['product'] . "\n"; ?></a>

            <?php   $stmt1 = $pdo->prepare('SELECT * FROM category WHERE parent_id = ?');
                    $stmt1->execute([$menu1['id']]);
                    $stmt1->fetch(); ?>
                    <ul>
                        <?php while($menu2 = $stmt1->fetch()){ ?>
                        <li><a href="<?php echo $menu2['category_link'] . "\n"; ?>"><?php echo $menu2['product'] . "\n"; ?></a></li>
                        <?php } ?>
                    </ul>


        </li>
<?php } ?>
</ul>
</body>
</html>

现在使用上面的php代码显示菜单树的数据：

实际数据如下：

从数据库中提取：

Answer 1

您正在使用其他提取$stmt1->fetch(); ?>，该提取会跳过第一个类别For Sale

<?php 
require_once 'include/dbpdo.php'; 
?>
<html>
<head>
<style>


</style>
</head>
<body>
<?php
$stmt = $pdo->query('SELECT * FROM `category` where `parent_id` = 0');
$stmt->execute();
?>
<ul>
    <?php while($menu1 = $stmt->fetch()){ ?>
        <li><a href="<?php echo $menu1['category_link'] . "\n"; ?>"><?php echo $menu1['product'] . "\n"; ?></a>

            <?php   $stmt1 = $pdo->prepare('SELECT * FROM category WHERE parent_id = ?');
                    $stmt1->execute([$menu1['id']]);
                    ?>
                    <ul>
                        <?php while($menu2 = $stmt1->fetch()){ ?>
                        <li><a href="<?php echo $menu2['category_link'] . "\n"; ?>"><?php echo $menu2['product'] . "\n"; ?></a></li>
                            <?php
                                $stmt2 = $pdo->prepare('SELECT * FROM category WHERE parent_id = ?');
                                $stmt2->execute([$menu2['id']]);
                                if($stmt1->rowCount()) echo "<ul>";
                                while($menu3 = $stmt2->fetch()){
                                    echo "<li>".$menu3['product'] ."</li>";
                                }
                                if($stmt1->rowCount()) echo "</ul>";

                            ?>
                        <?php } ?>
                    </ul>


        </li>
<?php } ?>
</ul>
</body>
</html>

Answer 2

您可以使用此代码：

<?php require_once 'include/dbpdo.php'; ?>
<html>
<head>
<style>


</style>
</head>
<body>
<?php
$stmt = $pdo->query('SELECT * FROM `category` where `parent_id` = 0');
$stmt->execute();
$menues = $stmt->fetchAll();
?>
<ul>
<?php
    foreach ($menues as $menuL1){
        if ($menuL1['parent_id'] == 0) {
            echo '<li><a href="' . $menuL1['category_link'] . '">' . $menuL1['product'] . '</a><ul>';
                foreach ($menues as $menuL2) {
                    if ($menuL2['parent_id'] == $menuL1['id']) {
                            echo '<li><a href="' . $menuL2['category_link'] . '">' . $menuL2['product'] . '</a><ul>';
                            foreach ($menues as $menuL3) {
                                if ($menuL3['parent_id'] == $menuL2['id']) {
                                    echo '<li><a href="' . $menuL3['category_link'] . '">' . $menuL3['product'] . '</a></li>';
                                }
                            }
                            echo '</ul></li>';
                    }
                }
            echo '</ul></li>';
        }
    }
?>
</ul>
</body>
</html>

Answer 3

你也可以通过以下功能来实现：

<?php require_once 'include/dbpdo.php'; ?>
<html>
<head>
<style>


</style>
</head>
<body>
<?php

function getMenu($level) {
    $stmt = $pdo->query('SELECT * FROM `category` where `parent_id` = ' . $level);
    $stmt->execute();
    return $stmt->fetchAll();
}

function child($parentId) {
    $return = [];
    $array = getMenu($parentId);
    foreach ($array as $arr) {
        if ($arr['parent_id'] == $parentId) {
            $return[] = $arr;
        }
    }
    return $return;
}

function listGen($parentId = 0) {
    $html = '<ul>';
    $array = child($parentId);
    foreach ($array as $arr) {
        $html .= '<li><a href="' . $arr['category_link'] . '">' . $arr['product'] . '</a>';
        $html .= listGen($arr['id']);
        $html .= '</li>';
  }
    $html .= '</ul>';
    return $html;
}

echo listGen();

?>
</body>
</html>

菜单树没有显示

3 个答案:

菜单树没​​有显示

3 个答案:

菜单树没有显示