Help with a Query

Hi to all, I'm new on this field, I've done various researches on the web to find out how I can realize this script in php:
I'm trying to make a call, query, with my mySQL database to show the result of the query into a container (web page) in Drupal. My script is attached below:

$conn = mysql_connect(`Host`, `admin`, `pssw`);
mysql_select_db(`nameOfDatabase`);

$cur = mysql_query ("

SELECT ((select SUM(`Q2`)
FROM `TableName`
where `SEGNO`= 2 AND `Q2` >= 1.01 AND `Q2` <= 4  AND `V2` >= 0.55 AND `V2` <= 0.65 )
-
(select COUNT(*)
FROM `TableName`
where `SEGNO`= 2 AND `Q2` >= 1.01 AND `Q2` <= 4  AND `V2` >= 0.55 AND `V2` <= 0.65 )
-
(select COUNT(*)
FROM `TableName`
where `SEGNO`<> 2 AND `Q2` >= 1.01 AND `Q2` <= 4  AND `V2` >= 0.55 AND `V2` <= 0.65 ))
/
(select COUNT(*)
FROM `TableName`
where `Q2` >= 1.01 AND `Q2` <= 4  AND `V2` >= 0.55 AND `V2` <= 0.65 )
as tot

");

mysql_close($conn);

the piece of code is working well in SQL Query, it gave me back the result of the calculation in one string number...

In Drupal I received an empty space and I'm in duobt about lines error notices:

Il Pagina base Query è stato aggiornato.

Messaggio di errore

Notice: shell_exec() has been disabled for security reasons in eval() (linea 3 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 3 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 3 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 4 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 3 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 3 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 3 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).
Notice: shell_exec() has been disabled for security reasons in eval() (linea 4 di /membri/soccerpro/portale/modules/php/php.module(80) : eval()'d code).

Any help is really appreciated.

Giorgio