TP5 首页导航一级和二级分类

public function  getNavCates(){
  //获取导航列表及子列表
  $cateres=db('cate')->where('pid',0)->select();
  foreach ($cateres as $k=> $v){
     $children=db('cate')->where('pid',$v['id'])->select();
     if($children){
       $cateres[$k]['children']=$children;
       // dump($children);die;
     }else{
       $cateres[$k]['children']=0;
     }
  }
  // dump($cateres);die;
  $this->assign('cateres',$cateres);
}