如何递归格式化PHP嵌套分类数组的完整树形结构？

原始分类数组（从MySQL获取） #

$data = [
  [
    'categoryId' => '08adf337-a577-4038-86a6-a5cd16676dff',
    'name' => 'ELECTRONICS',
    'parentId' => 0,
    'lft' => 1,
    'rgt' => 20,
    'level' => 0,
  ],
  [
    'categoryId' => '20150966-bbc5-438f-b3eb-1ff0bbc71b8b',
    'name' => 'TELEVISIONS',
    'parentId' => '08adf337-a577-4038-86a6-a5cd16676dff',
    'lft' => 2,
    'rgt' => 9,
    'level' => 1,
  ],
  [
    'categoryId' => '3fb68583-b9f3-4996-86fa-897c825767e4',
    'name' => 'TUBE',
    'parentId' => '20150966-bbc5-438f-b3eb-1ff0bbc71b8b',
    'lft' => 3,
    'rgt' => 4,
    'level' => 2,
  ],
  [
    'categoryId' => 'bca4d77f-9f6f-41da-ad66-e747edcb9482',
    'name' => 'LCD',
    'parentId' => '20150966-bbc5-438f-b3eb-1ff0bbc71b8b',
    'lft' => 5,
    'rgt' => 6,
    'level' => 2,
  ],
  [
    'categoryId' => '9726c8ff-7664-4494-bb2f-3b365e7a6743',
    'name' => 'PLASMA',
    'parentId' => '20150966-bbc5-438f-b3eb-1ff0bbc71b8b',
    'lft' => 7,
    'rgt' => 8,
    'level' => 2,
  ],
  [
    'categoryId' => '576a2266-9f11-4430-b81f-2ac2a536ad9a',
    'name' => 'PORTABLE ELECTRONICS',
    'parentId' => '08adf337-a577-4038-86a6-a5cd16676dff',
    'lft' => 10,
    'rgt' => 19,
    'level' => 1,
  ],
  [
    'categoryId' => '062921a4-e9af-48f6-adba-d623ca2de4ae',
    'name' => 'MP3 PLAYERS',
    'parentId' => '576a2266-9f11-4430-b81f-2ac2a536ad9a',
    'lft' => 11,
    'rgt' => 14,
    'level' => 2,
  ],
  [
    'categoryId' => '3a80ae89-5eba-4407-819c-944e1d360ed9',
    'name' => 'FLASH',
    'parentId' => '062921a4-e9af-48f6-adba-d623ca2de4ae',
    'lft' => 12,
    'rgt' => 13,
    'level' => 3,
  ],
  [
    'categoryId' => '0a03f267-8646-4460-bce7-dc6993e337a3',
    'name' => 'CD PLAYERS',
    'parentId' => '576a2266-9f11-4430-b81f-2ac2a536ad9a',
    'lft' => 15,
    'rgt' => 16,
    'level' => 2,
  ],
  [
    'categoryId' => 'fc9a25d0-a67a-4753-aed8-c148c9c95573',
    'name' => '2 WAY RADIOS',
    'parentId' => '576a2266-9f11-4430-b81f-2ac2a536ad9a',
    'lft' => 17,
    'rgt' => 18,
    'level' => 2,
  ],
];

目标树形结构格式 #

$result = array();
$result['items'] = [
    [
      'id' => '08adf337-a577-4038-86a6-a5cd16676dff',
      'title' => 'ELECTRONICS',
      'children' =>  [
        [ 'id' => '20150966-bbc5-438f-b3eb-1ff0bbc71b8b', 'title' => 'TELEVISIONS' ],
        [ 'id' => '3fb68583-b9f3-4996-86fa-897c825767e4', 'title' => 'TUBE' ],
        [ 'id' => 'bca4d77f-9f6f-41da-ad66-e747edcb9482', 'title' => 'LCD' ],
        [ 'id' => '9726c8ff-7664-4494-bb2f-3b365e7a6743', 'title' => 'PLASMA' ],
        [
          'id' => '576a2266-9f11-4430-b81f-2ac2a536ad9a',
          'title' => 'PORTABLE ELECTRONICS',
          'children' => [
            [
              'id' => '062921a4-e9af-48f6-adba-d623ca2de4ae',
              'title' => 'MP3 PLAYERS',
              'children' => [
                [ 'id' => '3a80ae89-5eba-4407-819c-944e1d360ed9', 'title' => 'FLASH' ]
              ]
            ],
            [ 'id' => '0a03f267-8646-4460-bce7-dc6993e337a3', 'title' => 'CD PLAYERS' ],
            [ 'id' => 'fc9a25d0-a67a-4753-aed8-c148c9c95573', 'title' => '2 WAY RADIOS' ]
          ],
        ],
      ],
    ]
];

PHP实现代码 #

方法1：递归构建（代码简洁，适合中小数据量） #

function buildTree(array $data, $parentId = 0) {
    $tree = [];
    foreach ($data as $item) {
        if ($item['parentId'] == $parentId) {
            $node = [
                'id' => $item['categoryId'],
                'title' => $item['name']
            ];
            // 递归查找当前节点的子节点
            $children = buildTree($data, $item['categoryId']);
            if (!empty($children)) {
                $node['children'] = $children;
            }
            $tree[] = $node;
        }
    }
    return $tree;
}

// 生成目标结构
$result = [
    'items' => buildTree($data)
];

// 输出结果验证
print_r($result);

方法2：非递归构建（性能更优，适合大数据量） #

function buildTreeNonRecursive(array $data) {
    // 按parentId分组所有节点，便于快速查找子节点
    $nodeGroups = [];
    foreach ($data as $item) {
        $nodeGroups[$item['parentId']][] = [
            'id' => $item['categoryId'],
            'title' => $item['name'],
            'parentId' => $item['parentId']
        ];
    }

    // 从根节点开始构建树形结构
    $tree = $nodeGroups[0] ?? [];
    foreach ($tree as &$node) {
        if (isset($nodeGroups[$node['id']])) {
            $node['children'] = $nodeGroups[$node['id']];
            // 用栈处理深层子节点
            $stack = $node['children'];
            while (!empty($stack)) {
                $child = array_pop($stack);
                if (isset($nodeGroups[$child['id']])) {
                    $child['children'] = $nodeGroups[$child['id']];
                    array_push($stack, ...$child['children']);
                    // 更新子节点数据
                    foreach ($node['children'] as &$c) {
                        if ($c['id'] == $child['id']) {
                            $c = $child;
                            break;
                        }
                    }
                }
                unset($child['parentId']);
            }
        }
        unset($node['parentId']);
    }

    return $tree;
}

// 生成目标结构
$result = [
    'items' => buildTreeNonRecursive($data)
];

// 输出结果验证
print_r($result);

参考MySQL相关语句 #

分类表结构 #

CREATE TABLE categories (
    categoryId VARCHAR(36) PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    parentId VARCHAR(36) DEFAULT '0',
    lft INT NOT NULL,
    rgt INT NOT NULL,
    level INT NOT NULL,
    INDEX idx_parentId (parentId),
    INDEX idx_lft_rgt (lft, rgt)
);

数据插入SQL #

INSERT INTO categories (categoryId, name, parentId, lft, rgt, level) VALUES
('08adf337-a577-4038-86a6-a5cd16676dff', 'ELECTRONICS', '0', 1, 20, 0),
('20150966-bbc5-438f-b3eb-1ff0bbc71b8b', 'TELEVISIONS', '08adf337-a577-4038-86a6-a5cd16676dff', 2, 9, 1),
('3fb68583-b9f3-4996-86fa-897c825767e4', 'TUBE', '20150966-bbc5-438f-b3eb-1ff0bbc71b8b', 3, 4, 2),
('bca4d77f-9f6f-41da-ad66-e747edcb9482', 'LCD', '20150966-bbc5-438f-b3eb-1ff0bbc71b8b', 5, 6, 2),
('9726c8ff-7664-4494-bb2f-3b365e7a6743', 'PLASMA', '20150966-bbc5-438f-b3eb-1ff0bbc71b8b', 7, 8, 2),
('576a2266-9f11-4430-b81f-2ac2a536ad9a', 'PORTABLE ELECTRONICS', '08adf337-a577-4038-86a6-a5cd16676dff', 10, 19, 1),
('062921a4-e9af-48f6-adba-d623ca2de4ae', 'MP3 PLAYERS', '576a2266-9f11-4430-b81f-2ac2a536ad9a', 11, 14, 2),
('3a80ae89-5eba-4407-819c-944e1d360ed9', 'FLASH', '062921a4-e9af-48f6-adba-d623ca2de4ae', 12, 13, 3),
('0a03f267-8646-4460-bce7-dc6993e337a3', 'CD PLAYERS', '576a2266-9f11-4430-b81f-2ac2a536ad9a', 15, 16, 2),
('fc9a25d0-a67a-4753-aed8-c148c9c95573', '2 WAY RADIOS', '576a2266-9f11-4430-b81f-2ac2a536ad9a', 17, 18, 2);

树形数据查询SQL（嵌套集模型） #

-- 查询完整树形结构，按lft排序保证层级顺序
SELECT * FROM categories ORDER BY lft ASC;

-- 查询指定节点的所有子节点
SELECT c.* 
FROM categories c
JOIN categories parent ON c.lft > parent.lft AND c.rgt < parent.rgt
WHERE parent.categoryId = '08adf337-a577-4038-86a6-a5cd16676dff'
ORDER BY c.lft ASC;

内容的提问来源于stack exchange，提问作者Ersin Güvenç