最近做一个足球赛事的功能，查询赛事需要更具 洲 - 国 - 赛事几级联动查询所以前端给的数据格式是：

[{
        value: '3', #洲id 
        label: '亚洲联赛',  #洲名称 
        children: [{
                value: '45',   #国id 
                label: '中国', #国昵称 
                children: [{
                        value: '53438',   #赛事id 
                        label: '中女超杯' #赛事昵称
                }, {
                        value: '534389',
                        label: '中女超'
                }]
        }, {
                value: '47',
                label: '南韩',
                children: [
                  {
                        value: '53333',
                        label: '韩K2联'

                  }, {
                        value: '54085',
                        label: '韩K4联'
                }]
        }]， 
          value: '1',  #洲id 
          label: '欧洲联赛',  #洲名称 
          children: [{
                  value: '45',   #国id 
                  label: '中国', #国昵称 
                  children: [{
                          value: '53438',   #赛事id 
                          label: '中女超杯' #赛事昵称
                  }, {
                          value: '534389',
                          label: '中女超'
                  }]
          }, {
                  value: '47',
                  label: '南韩',
                  children: [
                        {
                          value: '53333',
                          label: '韩K2联'

                        }, {
                          value: '54085',
                          label: '韩K4联'
                  }]
          }]
}]

最后大费周折还请教别人（之前搞过很久没搞忘记了） 才搞定，上实现代码：

            $result = [
                ['value' =>0,'label' =>'国际联赛'],
                ['value' =>1,'label' =>'欧洲联赛'],
                ['value' =>2,'label' =>'美洲联赛'],
                ['value' =>3,'label' =>'亚洲联赛'],
                ['value' =>4,'label' =>'大洋洲联赛'],
                ['value' =>5,'label' =>'非洲联赛'],
            ];


            foreach ($result as $k => &$v) {
                    $v['children'] = array_map('get_object_vars',DB::select("select countryId as value,countryCn as label from `league` where (`areaId` = {$v['value']}) group by `countryCn`"));
            }

            foreach ($result as $k => &$v) {
                foreach ($v['children'] as $k1 => &$v1) {
                    $v1['children'] = array_map('get_object_vars',DB::select("select id as value,nameChsShort as label from `league` where (`areaId` = {$v['value']}) and (`countryId` = {$v1['value']})"));

            }
        }