php - クエリは phpMyAdmin では機能しますが、mysql_query では機能しません

Question

私は困惑しています。phpMyAdmin ではクエリが機能するのに、MAMP 環境では機能しないのはなぜですか? MAMPで0の結果を返したクエリをエコーアウトし、それをコピーしてphpMyAdminに貼り付けたところ、同じクエリが期待される結果を返しました。

select
   c.id
from
    (select id, business_id 
     from coup 
     where match(name) against ('$search')
    ) as c
    left join
       (select business_id 
        from bus 
        where match(name, category, subcat) against ('$search')
       ) as b on
        c.business_id = b.business_id 
    inner join bloc z on
        c.business_id = z.business_id
where
    z.zip = '$zip'

以下は、コードに表示される行です

$q = "select c.id from (select id, business_id from ".TBL_COUPONS." where match(name) against ('".$search."')) as c left join (select business_id from ".TBL_BUSINESS." where match(name, category, subcat) against ('".$search."')) as b on c.business_id = b.business_id inner join ".TBL_BLOCATION." as l on c.business_id = l.business_id where l.zip = '".$zip."'";
$rs = mysql_query($q) or die(mysql_error());
$rec = array();
while(($row = mysql_fetch_array($rs)) !== FALSE ){
    $rec[] = $row[0];   
}

echo $q ショー:

select c.id from (select id, business_id from coupons where match(name) against ('walk')) as c left join (select business_id from business where match(name, category, subcat) against ('walk')) as b on c.business_id = b.business_id inner join buslocations as l on c.business_id = l.business_id where l.zip = '91326'