[PHP] thinkphp5框架实现数据库读取的数据转换成json格式示例

$category = DB::name('Category');
$category_list = $category->select();
$data=$this->list_to_tree($category_list,'category_id','category_parent_id','children'); //调用下面的方法
$data=$this->findChild($data);
header('Content-Type:application/json; charset=utf-8');
exit(json_encode($data,JSON_UNESCAPED_UNICODE));
// return $this->fetch('index');
$this->ajaxReturn($data, 'JSON');

function findChild($arr){
  static $tree=array();
  foreach ($arr as $key=>$val){
    $tree[]=$val;
    if (isset($val['_child'])){
    $this->findChild($val['_child']);
    }
  }
return $tree;
}
/**
 * 把返回的数据集转换成Tree
 * @access public
 * @param array $list 要转换的数据集
 * @param string $pid parent标记字段
 * @param string $level level标记字段
 * @return array
 */
function list_to_tree($list, $pk='id',$pid = 'pid',$child = '_child',$root=0) {
  // 创建Tree
  $tree = array();
  if(is_array($list)) {
  // 创建基于主键的数组引用
  $refer = array();
  foreach ($list as $key => $data) {
  $refer[$data[$pk]] =& $list[$key];
  }
  foreach ($list as $key => $data) {
  // 判断是否存在parent
  $parentId = $data[$pid];
  if ($root == $parentId) {
  $tree[] =& $list[$key];
  }else{
  if (isset($refer[$parentId])) {
    $parent =& $refer[$parentId];
    $parent[$child][] =& $list[$key];
  }
  }
  }
  }
  return $tree;
}