Description:
------------
If I change the current 'SELECT' to 'SELECT * FROM...' the script works fine. Otherwise PHP shows me the follow warning:


Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in /opt/lampp/htdocs/distri/functions.php on line 158

Test script:
---------------
function get_productos($link,$params = null){
    $query =   "SELECT p.id, p.codigo, p.nombre, f.nombre as familia, pro.nombre as provedor, p.precio, p.tamaño, p.medida
                FROM productos p
                INNER JOIN familias f ON p.familia = f.id
                INNER JOIN provedores pro ON p.provedor = pro.id";

    $result = mysql_query($query, $link);
    $i = 0;$productos = array();
    while($data = mysql_fetch_assoc($result)){
        foreach($data as $key => $valor){
            $productos[$i][$key] = $valor;
        }
        $i++;
    }

    mysql_close($link);
    return $productos;
}

Expected result:
----------------
I expect fill the array $prod with data.

Actual result:
--------------
Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in /opt/lampp/htdocs/distri/functions.php on line 158