DB query error while Error Handling

I wrote the following snippet in order to handle errors.

(Page.php gets included in index page through : array( falseNamePage=> page.php, ....ect))

Perfoming some tests to see how it reacts, I delete a page.php from public_html.

RESULT :

-error logging ok

-alert email sending ok

-recording in DB : ERROR :

Notice: Undefined variable: $database in /home/.../public_html/index.php on line 40

Warning: mysql_query() expects parameter 2 to be resource, null given in /home/.../public_html/index.php on line 40 "impossible to connect with DB2"

I do not understands why it fails connecting to the DB in this case and sends back an error.

DB Connection works fine in every other cases ( delete, select,update, insert ...)

function errorHandler($errno, $errstr, $errfile, $errline)
    {
    require_once('connection.php');
    $now = time();
    $date = date("Y-m-d H:i:s",$now);    
    switch ($errno) {
        case E_NOTICE:
        case E_USER_NOTICE:
        case E_DEPRECATED:
        case E_USER_DEPRECATED:
        case E_STRICT:

            ............ 5 first cases code...............

        case E_WARNING:
        case E_USER_WARNING:            

            $message_warning = "Warning : ".$errno." : ".$errstr." : ".$errfile." : ".$errline;
            error_log ( $message_warning ,0);
            $mail = '[email protected]';  $sujet = $message_warning;  $body_warning = $date." : ".$message_warning;                             
            mail($mail,'=?UTF-8?B?'.base64_encode($sujet).'?=',stripslashes($body_warning));
            $query_warning  =" INSERT INTO errorlog (severity,errno,errstr,errfile,errline,time) 
            VALUES ('WARNING','".$errno."','".$errstr."','".$errfile."','".$errline."','".$date."')";           
            $result_warning = mysql_query($query_warning,$database) or die("impossible to connect with DB2");
                break;

        case E_ERROR:
        case E_USER_ERROR:

       ............... 2 last cases code ..........
    }       
}    
set_error_handler("errorHandler");  

The final question is :

WHY IS AN INCLUDE ERROR ECHOED 4 TIMES ?

Does the system attempts 4 times to "open stream"?

I did :

function errorHandler($errno, $errstr, $errfile, $errline)
           {
        if     ($errno == E_NOTICE )
        { echo "<br/>".$errno."== E_NOTICE<br/>";}
        if     ($errno == E_USER_NOTICE)
        { echo "<br/>".$errno."== E_USER_NOTICE<br/>";}
        if     ($errno == E_DEPRECATED)
        { echo "<br/>".$errno."== E_DEPRECATED<br/>";}
        if     ($errno == E_USER_DEPRECATED)
        { echo "<br/>".$errno."== E_USER_DEPRECATED<br/>";}
        if     ($errno == E_STRICT)
        { echo "<br/>".$errno."== E_STRICT<br/>";}
        if     ($errno == E_WARNING)
        { echo "<br/>".$errno."== E_WARNING<br/>";}
        if     ($errno == E_USER_WARNING)
        { echo "<br/>".$errno."== E_USER_WARNING<br/>";}
        if     ($errno == E_ERROR)
        { echo "<br/>".$errno."== E_ERROR<br/>";}
        if     ($errno == E_USER_ERROR)
        { echo "<br/>".$errno."== E_USER_ERROR<br/>";}
           }             
           set_error_handler("errorHandler");   

RESULT :

2== E_WARNING

2== E_WARNING

2== E_WARNING

2== E_WARNING