无限级分类数据表设计

@callback 已经更新

@Reason_bobo 创建一个 Generator 实例，调用make方法，第一个参数是原始数组或集合，第二个是主键，第三个是父键的字段名，第四个是生成的子元素保存在父元素的那个属性下面，第五个是顶级元素的主键值。
举个例子：

<?php
    $menus = [
        [
            'id' => 1,
            'parent_id' => 0,
            'label' => 'Dashboard',
            'link' => '/dashboard',
            'icon' => null,
            'roles' => 'Admin,'
        ],
        [
            'id' => 2,
            'parent_id' => 1,
            'label' => 'Fiance',
            'link' => '/dashboard/finace',
            'icon' => null,
            'roles' => 'Admin,Fiance'
        ],
        [
            'id' => 3,
            'parent_id' => 1,
            'label' => 'Operation',
            'link' => '/dashboard/operation',
            'icon' => null,
            'roles' => 'Admin,Operation'
        ],
    ];

    $generator = new Generator();
    $tree = $generator->make($menus, 'id', 'parent_id', 'sub_menus', 0);

    # tree 的结果如下
    $tree = [
        [
            'id' => 1,
            'parent_id' => 0,
            'label' => 'Dashboard',
            'link' => '/dashboard',
            'icon' => null,
            'roles' => 'Admin,',
            'sub_menus' => [
                [
                    'id' => 2,
                    'parent_id' => 1,
                    'label' => 'Fiance',
                    'link' => '/dashboard/finace',
                    'icon' => null,
                    'roles' => 'Admin,Fiance'
                ],
                [
                    'id' => 3,
                    'parent_id' => 1,
                    'label' => 'Operation',
                    'link' => '/dashboard/operation',
                    'icon' => null,
                    'roles' => 'Admin,Operation'
                ]
            ]
        ]
    ];
?>