如何在php中按组发布mysql数据

我在构建查询并在PHP中显示结果时遇到问题，结果应该在PHP中分组

给定以下示例数据集：

+-----------+---------+
| category  | item    |
+-----------+---------+
| fruit     | apple   |
| fruit     | apricot |
| fruit     | banana  |
| fruit     | plum    |
| vegetable | carrot  |
| vegetable | onion   |
| vegetable | potato  |
| vegetable | spinach |
+-----------+---------+

和PHP/MySQL代码：

<?php

    include_once $_SERVER['DOCUMENT_ROOT'] . '/includes/magicquotes.inc.php';
    include $_SERVER['DOCUMENT_ROOT'] . '/includes/SQLTutorial.db.inc.php';

    echo "<p>Here is a test:</p>";

    try {
    $sql = "select category, item from Foods";
      $result = $pdo->query($sql);
    }
    
    catch (PDOException $e) {
      $error = 'Error fetching data: ' . $e->getMessage();
      include 'error.html.php';
      exit();
    }

    foreach ($result as $row)
    {
      $ShoppingItems[] = array(
        'category' => $row['category'],
        'item' => $row['item']
      );
    }

    echo "<p>Here are the items by group:</p>";
        
    foreach ($ShoppingItems as $ShoppingItem)
    {
        echo "<p><b>" . $ShoppingItem['category'] . "</b>" 
                . $ShoppingItem['item'] . "</p>";            
    }

?>

我应该如何编写查询和php，以便在单个标记中格式化类别，如

，并且项目后面有不同的标记，如

，因此结果如下所示

水果

• 苹果
• 杏
• 香蕉
• 李子

蔬菜

• 胡萝卜
• 洋葱
• 马铃薯
• 菠菜

会议上的回答非常有帮助。下面的代码工作得很好——尽管我确信有一个更优雅的解决方案

<?php

include_once $_SERVER['DOCUMENT_ROOT'] . '/includes/magicquotes.inc.php';
include $_SERVER['DOCUMENT_ROOT'] . '/includes/SQLTutorial.db.inc.php';

echo "<p>Here is a test:</p>";

try {
    $sql = "select * from Foods order by category, item";
    $result = $pdo->query($sql);
}
catch (PDOException $e) {
    $error = 'Error fetching data: ' . $e->getMessage();
    include 'error.html.php';
    exit();
}

// Loop through results and build the data into a data structure
foreach($result as $row){
    $category = $row['category'];
    $item = $row['item'];
    if (!isset($list[$category])) {// if this is this a category we've never seen before
        $list[$category] = array($item);//then add it to the list with a new array to hold its items.
    } else {
        $list[$category][] = $item;      //otherwise just push the new item onto the category's array of items.
    }    
}

/*        
print "<pre>\n";
print_r($list);  // <-- a very useful debugging tool
print "</pre>\n";
*/            

// And now to print out the formatted results.
foreach ($list as $category => $items) {
    echo "<h1>" . htmlspecialchars($category, ENT_COMPAT, "utf-8") . "</h1><ul>\n";
    foreach ($items as $item) {
        echo "<li>" . htmlspecialchars($item, ENT_COMPAT, "utf-8") . "</li>\n";
    }
    echo "</ul>\n";
}

?>

向我们展示您迄今为止编写的代码。来吧。任何关于PHP和MySQL的基础教程都会告诉您如何做到这一点。不够好。这个问题似乎离题了，因为它显示了负面的研究成果。我添加了示例代码，以便更好地寻求您的帮助。再次感谢。