php中异步树中的递归函数与“；致命错误:允许的内存大小为134217728“；

我曾尝试创建异步树，但当我调用函数内部的函数时，她给我带来了内存错误。我读过很多关于如何更改php内存限制以运行它的文章，我尝试过，但没有结果。但我真正想要的是一种"停止"函数的方法，而不是无限次地调用它。有人能帮我吗？

function treeview()
{    
    $i = 0;
    $result = array();
    $rs = mysql_query("select * from dados3 where nivel = 1");
    while($row = mysql_fetch_array($rs))
    {
        $node = array();
        $node['id'] = $row['id'];
        $node['text'] = $row['descricao'];
        $node['state'] = 'closed';
        $node['children'] = has_child($row['id']);
        array_push($result, $node);
    }  
echo json_encode($result);
}
function has_child($id){
    $result2 = array();
    $node_2 = array();
    $rs = mysql_query("select * from dados3 where id_nivel_superior=$id");
    $row = mysql_fetch_array($rs);
    $node_2['text'] = $row['descricao'];
    $node_2['state'] = 'closed';
    $node_2['children'] = has_child($id);
    array_push($result2, $node_2);
    return $result2;
}

我尝试了上面的方法，这会返回给我所有的子项为null，并且在级别3重复级别1。你认为这可能是错的吗？

function treeview()
{    
    $i = 0;
    $result = array();
    $rs = mysql_query("select * from dados3 where nivel = 1");
    while($row = mysql_fetch_array($rs))
    {
        $node = array();
        $node['id'] = $row['id'];
        $node['text'] = $row['descricao'];
        $node['state'] = 'closed';
        $node['children'] = has_child($row['id']);
        array_push($result, $node);
    }  
echo json_encode($result);
}
function has_child($id){
    $result2 = array();
    $node_2 = array();
    $rs = mysql_query("select * from dados3 where id_nivel_superior=$id");
    while($row = mysql_fetch_array($rs))
    {
        $node_2['text'] = $row['descricao'];
        $node_2['state'] = 'closed';
        $node_2['children'] = has_child($row['id']);
        array_push($result2, $node_2);
        return $result2;
    }
}

在图片中，您可以看到数据库结构和数据：

数据库的图像

我已经把return从循环中放了出来，但返回给我的json中的cidren都为null。在第4级（我想展示一些东西），它再次重复所有级别。

[{"id":"1","text":"1 - Cat.","state":"closed","children":[{"text":"1.1 - Sub.","state":"closed","children":[]},{"text":"1.2 - Sub.","state":"closed","children":[]},{"text":"1.3 - Sub.","state":"closed","children":[]}]},{"id":"2","text":"2 - Cat.","state":"closed","children":[{"text":"2.1 - Sub.","state":"closed","children":[{"text":"2.1.1 - Sub_sub","state":"closed","children":[{"text":"Faq 1 - categoria 1","state":"closed","children":[]}]}]},{"text":"2.2 - Sub.","state":"closed","children":[]},{"text":"2.3 - Sub.","state":"closed","children":[]}]},{"id":"4","text":"3- Cat.","state":"closed","children":[{"text":"3.1 - Sub.","state":"closed","children":[]},{"text":"3.2 - Sub.","state":"closed","children":[]},{"text":"3.3 - Sub.","state":"closed","children":[]}]},{"id":"5","text":"4 - Cat.","state":"closed","children":[{"text":"4.1 - Sub.","state":"closed","children":[]},{"text":"4.2 - Sub.","state":"closed","children":[]},{"text":"4.3 - Sub.","state":"closed","children":[]}]}]

如果你能帮我理解为什么孩子们没有出现，我将不胜感激。

致以最良好的问候。