PHP多层级菜单树形结构递归处理

如题：

一、数据库菜单数据表

使用图片中id和parent_id两个参数来关联父子关系

二、将数据库中的数据变成树状多层级解构

{ "id": 1, "parentId": 0, "treePath": "0", "name": "系统管理", "type": 2, "path": "/system", "component": "Layout", "perm": null, "visible": 1, "sort": 1, "icon": "system", "redirect": "/system/user", "createTime": "2021-08-28 09:12:21", "updateTime": "2021-08-28 09:12:21", "level": 0, "children": [ { "id": 2, "parentId": 1, "treePath": "0,1", "name": "用户管理", "type": 1, "path": "user", "component": "system/user/index", "perm": null, "visible": 1, "sort": 1, "icon": "user", "redirect": null, "createTime": "2021-08-28 09:12:21", "updateTime": "2021-08-28 09:12:21", "level": 1, "children": [ { "id": 31, "parentId": 2, "treePath": "0,1,2", "name": "用户新增", "type": 4, "path": "", "component": null, "perm": "sys:user:add", "visible": 1, "sort": 1, "icon": "", "redirect": "", "createTime": "2022-10-23 11:04:08", "updateTime": "2022-10-23 11:04:11", "level": 2 }, ... // 多层级省略 ] }, ... // 多层级省略 ] }, ... // 多层级省略

三、实现方法

```
// 1、先获取数据
$model = new SysMenu();
$data = $model->getDbAll();

// 2、重点: 组装菜单menus，可将该方法提取出来
function filterMenus($data, $pid = 0, $level = 0)
{
// $level 是可选
$tree = [];
foreach($data as $k => $v) {
if ($v['parent_id'] === $pid) {
$v['level'] = $level;
$child = filterMenus($data, $v['id'], $level+1);
if (!empty($child)) {
// 自定义children字段，存放子数据
$v['children'] = $child;
}
// 将$v push到$tree中，多维数组
$tree[] = $v;
}
}
return $tree;
}

// 3、调用函数
$menus = filterMenus($data, 0);

// 4、打印结果
var_dump($menus);die;
```

以上即可完成菜单转化，重点是数据表中两个关联字段id、parent_id和递归函数;