php递归查找无限分类(树结构)

一.数据库多次查询形式

1.原生方式

header("Content-type:text/html;charset=utf-8");
$conn = mysql_connect('localhost','root','123456');
mysql_select_db('test');
mysql_query("set names 'utf8'");
function getCate($pid = 0)
{
    //1.通过父级id获得子级list
    $sql = "select * from cate where pid=".$pid;
    $res = mysql_query($sql);
    if($res)
    {
        while($row = mysql_fetch_assoc($res)){
            $categories[] = $row;
        }
    }

    //2.获取某级分类及子分类(无限tree) (重点)
    if(0 < count($categories))
    {
        for($i = 0; $i < count($categories); $i++)
        {
            $categories[$i]['child'] = getCate($categories[$i]['id']);
        }
    }

    return $categories;
}

//测试调用
$cate = getCate(0);

2.写在了DAO层

    //通过父级id获得子级list
    public function getCatByPid(int $pid){
        $where  = ['pid'=>$pid,'is_show'=>1];
        $res = $this->getModel()->where($where)->select()->toArray();
        return $res;
    }

    //获取某级分类及子分类(无限tree)
    public function getCategory(int $id){

        //1.通过父级id获得子级list
        $categories = $this->getCatByPid($id);

        //2.获取某级分类及子分类(无限tree) (重点)
        if(count($categories) > 0) {
            for ($i = 0; $i < count($categories); $i++) {
                $categories[$i]['child'] = $this->getCategory($categories[$i]['id']);
            }
        }

        return $categories;
    }

控制器调用 ： $res = $this->service->getCategory(0);

二.数据库一次查询出一维数组list,再通过递归生成树结构

1.原生

private function tree_data(&$list, $parent){
    $tree = array();
    foreach($list as $row) {
        if($row['permission_parent_id'] == $parent) {

            $row['children'] = $this->tree_data($list, $row['permission_id']);
            $tree[] = $row;
        }
    }
    return $tree;
}

2.写在了DAO层

    //获得所有分类（不考虑树型接口，再逻辑层处理）
    public function getAll(){
        $where  = ['is_show'=>1];
        //1.查出所有一维数组
        $res = $this->getModel()->where($where)->select()->toArray();
        //2.生成树结构
        $cat_tree = $this->treeData($res, 0);
        return $cat_tree;

    }


    //递归生成树型结构
    function treeData(&$list, $parent_id){
        $tree = array();
        foreach($list as $row) {
            if($row['pid'] == $parent_id) {

                $row['child'] = $this->treeData($list, $row['id']);
                $tree[] = $row;
            }
        }
        return $tree;
    }

控制器调用 ： $res = $this->service->getAll();//一维数组查找分类全部数据

转：https://www.cnblogs.com/in-loading/archive/2012/05/24/2516302.html

https://www.cnblogs.com/chenkg/p/6088259.html

https://blog.csdn.net/u012767761/article/details/82776969