php pdo recursive function for navigation menu

Question

Im trying to do a menu with with rows coming from the database, i have been reading here in stackoverflow about doing a recursive function to evaluate the parentId and Id and build the lower levels options, but with no luck. also tried to convert the sql answer to a multidimensional array with no luck...

Basically what i need is to build the set of list elements according to the parent, for example Dashboard.php is the parent of son.php

Here is my code:

function buildMenu($userType){

    try{

        $db   = new db();
        $conn = $db->conn();

        $SQL_BUILD_MENU = "select usertypes.id as menuId, 
        menu.name as menuName, menu.link as menuLink, 
        usertype_menu.parent_id as 
        parent from usertypes inner join usertype_menu on usertypes.id =                                usertype_menu.usertype_id inner join 
        menu on usertype_menu.menu_id = 
        menu.id where usertypes.name='".$userType."'";

        $conn->prepare($SQL_BUILD_MENU);
        foreach($check = $conn->query($SQL_BUILD_MENU) as $row) {
                echo "<ul>";
                echo "<a href=".$row['menuLink']."><li>" . $row['menuName'] . "</li></a>";
                echo "</ul>";        
        }

    }

    catch(Exception $e){

        echo "Se ha presentado un error en buildMenu".$e;

        }


    }

}


+----+--------+-------------+-----------------+--------+
| id | menuId | menuName    | menuLink        | parent |
+----+--------+-------------+-----------------+--------+
|  1 |      1 | Dashboard   | dashboard.php   | 0      |
|  2 |      1 | Interaction | interaction.php | 0      |
|  3 |      1 | Son         | Son.php         | 1      |
+----+--------+-------------+-----------------+--------+

Thanks in advance.

Answer 1

Firstly, sanitise your query. Use a prepared statement and bind the paramater, don't string add.

Secondly, get all of the relevant data at once and build a data structure from it. Recursion is not the answer here.

Thirdly, unordered lists cannot have text as children. You need to encapsulate them in LI nodes.

<ul>
   <li>Example 1</li>
   <li>Example 2</li>
   <li>
     Example 3 with a child list
     <ul>
        <li>Example 3 Child 1</li>
     </ul>
   </li>
</ul>

• Example 1
• Example 2
• Example 3 with a child list
  • Example 3 Child 1