Organize Listing by mysql data parent item in php

Question

I have a list to do that will work as follows:

<li id="1">Pai
    <ul>
        <li id="2">Item 01</li>
        <li id="3">Item 02
            <ul>
                <li id="4">Item 03</li>
            </ul>
        </li>
    </ul>
</li>

Data is rescued from a Mysql table with the following format:

ID  ||  titulo    ||    pai
1   ||  Pai       ||    0
2   ||  Item 01   ||    1
3   ||  Item 02   ||    1
4   ||  Item 03   ||    3

The'parent 'field is based on the item ID.

How do I organize this via PHP?

Answer 1

You must use a recursive Function that shows all the descending elements of the level that is passed in the function.

Below follows my code that shows a menu the same way you want. You have to remove what doesn’t matter.

To point out that my function QSelect returns the recordset of the query that is passed.

---

function menuTree($nivel, $id,$CAT) {

    $aCAT=explode('_',$CAT);
    $nivel++;
    $query="SELECT category_id,name  FROM categories WHERE is_active=1 and category_id_parent = $id order by sort,name asc ;";
    $QSelect=QSelect($query,0);
    $link='';

    $class_nivel_index=$nivel; //Como não ha classes para todos os niveis, isto vai limitar as opções
    if ($class_nivel_index>2){$class_nivel_index=2;}

    $class_menu=array('vertical-menu','sub-vertical-menu','sub-sub-vertical-menu');
    $class_menu_active=array('vertical-menu-active','sub-vertical-menu-active','sub-sub-vertical-menu-active');


    for ($r = 0; $r <= $nivel; $r++) {$link .=$aCAT[$r].'_';}
    {

        if($QSelect[0]['category_id']>0)
        {foreach ($QSelect as $row) {
            $linkCAT=$link . $row['category_id'];

            if (isset($aCAT[$nivel+1]) and $aCAT[$nivel+1]==intval($row['category_id'])){
                $Class=$class_menu_active[$class_nivel_index];
            }else{
                $Class=$class_menu[$class_nivel_index];

            }

            echo '<a href="/?OP=INDEX_SHOPPING&CAT=' . $linkCAT . '">';
            echo '<p class="' . $Class.'">';
                echo $row['name'];
            echo '</p>';
            echo '</a>';
            if (isset($aCAT[$nivel+1]) and $aCAT[$nivel+1]==intval($row['category_id'])){
                    menuTree($nivel, $row['category_id'],$CAT . '_' . $row['category_id']);
            }
        }
        }
    }
}

Call from the main programme :

menuTree(-1,0,$CAT);