Select in suggest php, relation many-to-many

See more:

SQL

MySQL

database

I need help with a select, but before asking the question, I will give a short description of how my system works:

my database has a many-to-many relationship, look below:

table product:
prd_cod(pk) //stores the product code ex: 0,1,2
cat_cod(fk)
prd_name //stores the product name, ex: tv, gps, notebook

table description_characteristc:
prd_cod(fk)
id_characteristic(fk)
description //stores the description of the characteristic, ex: sony, 1kg, hj10

table characteristic:
id_characteristic (pk)
name_characteristic //store the name of characteristic, ex: brand, weight, model

i have ready made in the index.php, a suggest jquery, that every word I type it's calls the suggest.php look below, that makes a select and returns the result into the suggestion box in the index.

header('Content-type: text/html; charset=UTF-8');

$hostname = 'localhost';

$username = 'root';

$password = '';

$dbname = 'cpd';



mysql_connect($hostname, $username, $password)or die('Erro ao tentar conecta o banco 
de dados.');


mysql_select_db( $dbname );



    if( isset( $_REQUEST['query'] ) && $_REQUEST['query'] != "" )

{
    $q = mysql_real_escape_string( $_REQUEST['query'] );



if( isset( $_REQUEST['identifier'] ) && $_REQUEST['identifier'] == "sugestao")

{
    $sql = "SELECT p.prd_name, d.description

    FROM product p

    INNER JOIN description_characteristc d using (prd_cod)

    WHERE '".$q."' like concat(p.prd_name, '%') AND

    concat(p.prd_name, ' ', d.description) like concat('".$q."', '%')LIMIT 10";



    $r = mysql_query( $sql );


    if ( $r )
{

    echo '<ul>'."\n";

    $cont = 0;

    while( $l = mysql_fetch_array( $r ) ){

        $p = $l['nome'];

        $p = preg_replace('/(' . $q . ')/i', '<span style="font-<br mode=" hold=" />                         weight:bold;">$1</span>',  

$l['prd_nome'].' '.$l['descricao'].' '.$l['descricao']);

echo "\t".'<li id="autocomplete_'.$cont.'">
      rel="'.$l['prd_nome'].'.'.$l['descricao'].'">'. utf8_encode( $p ) .':</li:>'."\n";
    $cont++;
    }

    echo ':</ul:>';


}
}


}



?>

questions:

1° currently when the user type 't', the select brings nothing, only when the user type 'tv' is bringing the result:

tv led
tv plasm
tv samsumg

i would like that when the user type 't' the select bring me - 'tv'

2° when you type 'tv plasm' it's bringing two times the same name_characteristic:

ex: tv plasm plasm

3° currently my select selects the prd_name and the descriptions of table description_characteristc, ex: tv led, I would like my select could make a inverse select too, ex: led tv.

4°I would like that when the results of the select were shown, could have a cache feature that shows the order of the most sought for the less sought.

remembering that prd_name stores only 'tv'

the help I'm looking for, can be in the form of select, as in the form of procedure, php file can also be edited, i thank you all.