Layered menu with PHP

Question

I have a table like this:

id title parent_id full_path 

full_path designed to search for a parent as recursive. Like this:

 +----+-----------+-----------+-----------+ | id | title | full_path | parent_id | +----+-----------+-----------+-----------+ | 40 | home | 40 | 0 | | 41 | myhome1 | 41 | 0 | | 42 | **** | 40-42 | 40 | | 43 | ***** | 41-43 | 41 | | 44 | *** | 44 | 0 | | 45 | **** | 45 | 0 | | 46 | ***** | 46 | 0 | | 49 | ****** | 49 | 0 | | 50 | **** ** | 40-42-50 | 42 | | 51 | **** ** | 40-42-51 | 42 | | 52 | **** ** | 40-42-52 | 42 | | 53 | ******* | 40-53 | 40 | | 54 | **** | 40-54 | 40 | | 55 | *** | 41-55 | 41 | | 56 | **** **** | 40-42-56 | 42 | | 57 | ******* | 44-57 | 44 | +----+-----------+-----------+-----------+ 

How can I get a recursive array as follows:

 array ( 40 => array ( 42 => array ( 50,51,52,etc. ), 53, 54 ) 41 => array ( 43, 55, ), 44 => array ( 57, ), etc... ) 

Is it possible to use full_path to create a multi-level menu?

Answer 1

You can use the code below for this. Keep in mind that this works because the array of your objects will be very small and the recursion that will be executed will be minimal. Do not use this approach for large arrays.

 <?php $query = "SELECT id, parent_id FROM subjects"; //execute with your prefered method, eg mysqli $rows = array(); while($row = $result->fetch_array(MYSQLI_ASSOC)) { $rows[] = $row; } function getChildren($p) { global $rows; $r = array(); foreach($rows as $row) { if ($row['parent_id']==$p) { $r[$row['id']] = getChildren($row['id']); } } return $r; } $final = getChildren(0); ?> 

Answer 2

I edited the Hugo code:

MySQL Code: sqlfiddle

Our table is as follows:

 ID | Categories_name | Parent_id 

our data (the numbers in the picture show the categories of identifiers):

our PHP codes:

 <?php $db=mysql_connect("127.0.0.1","root",""); $db_name = "test"; mysql_select_db($db_name,$db); $query = "SELECT `id`,`cat_name`,`parent_id` FROM `categories`"; $result=mysql_query($query); $num=mysql_num_rows($result); $level_each_rows = array(); $rows = array(); for($i = 0 ; $i < $num ; $i++) { $q_data = mysql_fetch_array($result); $rows[] = $q_data; } function getChildren_string($p) { global $rows; global $level_each_rows; $r = array(); $i = 0; $return = ''; foreach($rows as $row) { if ($row['parent_id'] == $p) { if($row['parent_id'] == 0) { $level_each_rows[$row['id']]['i'] = 0; } else { $level_each_rows[$row['id']]['i'] = $level_each_rows[$row['parent_id']]['i'] + 1; } $return = $return.' <tr> <td>'.$row['parent_id'].'</td> <td><div style="margin:0px '.($level_each_rows[$row['id']]['i'] * 35).'px;">['.$row['id'].'] - '.$row['cat_name'].'</div></td> </tr> '; $return = $return.getChildren_string($row['id']); $i++; } } //--- return $return; } $childs = getChildren_string(0); echo ' <div dir="ltr"> <table dir="ltr" border="1"> <tr> <td>Parent ID</td> <td>Child ID</td> </tr> '; echo $childs; echo ' </table> </div> '; ?> 

Result: