PHP get all matching rows in relational mysql innodb database

Question

I have made 3 tables in a DB with a many to many relationship. for variable $refernece_keys in my DB should return all of the related fields in the DB - but it is only returning the first assigned and ignoring the others.

eg page1 should return keys_href: id's 1, 2, 3, 4, 8, 10, 15 - however it only returns id:1 page2 should return keys href: id's 3, 4, 5, 7, 8, 11 - however it only returns id:3

Is there something wrong with my ARRAY?

$SQL = 
   "SELECT  * FROM learn_more AS lm 

LEFT JOIN  learn_more_to_reference_key AS lmtrk 
        ON  lm.id = lmtrk.learn_more_id 

LEFT JOIN  reference_keys AS rk 
        ON  rk.keys_id = lmtrk.reference_key_id

     WHERE  lm.page_title = '$this_page'";

$result = mysql_query($SQL) or die(mysql_error()); 

 while ($db_field = mysql_fetch_array($result))
{   
        $id                =     $db_field['id'];
        $main_title        =     $db_field['main_title'];
        $main_content     =     $db_field['main_content'];
        $reference_keys   =     $db_field['keys_href']; 
        $sub_title        =     $db_field['sub_title'];
        $sub_content      =     $db_field['sub_content'];
}

------------------------------------------------>EDIT

My PHP view page is a template

<div id="content">  
<div class="section_frame">


<div class="section_title">
<?php echo $main_title; ?>
</div>

<div class="section_content">
<?php echo $main_content; ?>
</div>


<div class="section_content_ref">
<span class="hl_reference"><u>key references:</u></span> 
<?php echo $reference_keys; ?>
</div>

<div class="sub_section_title">
<?php echo $sub_title; ?>
</div>

<div class="sub_section_content">
<?php echo $sub_content; ?>
</div>

so basically i just want my values to echo out..

Answer 1

Ah, my first thought would be that since your while loop runs over all the records, after it is finished only the last record is available... except you are only seeing the first one. if you were to add echo $id inside the while loop, do all the IDs get printed? Also, if you have some more code to complete the example that would help.

$items = array();
while ($db_field = mysql_fetch_array($result))
{   
    $id                =     $db_field['id'];
    $main_title        =     $db_field['main_title'];
    $main_content     =     $db_field['main_content'];
    $reference_keys   =     $db_field['keys_href']; 
    $sub_title        =     $db_field['sub_title'];
    $sub_content      =     $db_field['sub_content'];
    $items[$id] = array($main_title, $main_content, $reference_keys, $sub_title, $sub_content);
}

The above would create an array where the id of each record points to the record information. Is that along the lines of what you are going for?