PHP - 使用cURL将数据发送到Salesforce，但不在数据库中发布

my problem is that i'm working with salesforce in wordpress, i'm not using wordpress-to-lead plugin, I have a form in a template and that form sends data to salesforce via cURL and also is posting data in database cause I have to generate a password and then send it to the user but its not working, is working salesforce but not saving data in the database, here is my code to post data in database and generate the password

$keysString = implode(", ", array_keys($blank_section));
          unset($_POST['userId']);
            $user_id = mysql_query("SELECT MAX(id) AS id FROM int_form_data");
                $user_id = $user_id+11;
            $passwordSend = 'INTELIGOS'.rand(10000, 5000000);
            $array_user_id = array('user_id' => $user_id, 'password' => $passwordSend);
            $posted_data = array_merge($_POST,$array_user_id);
    foreach($posted_data as $k=>$v) {
        $itfdatainfo[$k] = $v;
    }



    $itfkeys    = array_keys($itfdatainfo);
    $itfvalues = array_values($itfdatainfo);

    if(isset($_POST['submit'])) {

     $sql = "INSERT INTO int_form_data (".implode(',',$itfkeys).") VALUES('".implode("','",$itfvalues)."')";        

        $result = mysql_query($sql);
    }

And here I use cURL to send data to Salesforce:

//Initialize the $query_string variable for later use
$query_string = "";
$kv = array();
//If there are POST variables
if ($_POST) {

//Initialize the $kv array for later use


//For each POST variable as $name_of_input_field => $value_of_input_field
foreach ($_POST as $llav => $value) {

//Set array element for each POST variable (ie. first_name=Arsham)
$kv[] = stripslashes($llav)."=".stripslashes($value);

}

//Create a query string with join function separted by &
$query_string = join("&", $kv);
}
//Check to see if cURL is installed ...
if (!function_exists('curl_init')){
die('Sorry cURL is not installed!');
}

//The original form action URL from Step 2 
$url = 'https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8';

//Open cURL connection
$ch = curl_init();

//Set the url, number of POST vars, POST data
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, count($kv));
curl_setopt($ch, CURLOPT_POSTFIELDS, $query_string);

//Set some settings that make it all work 
curl_setopt($ch, CURLOPT_HEADER, FALSE);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, FALSE);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

//Execute SalesForce web to lead PHP cURL
$result = curl_exec($ch);

//close cURL connection
curl_close($ch);

Anyone knows why is happening that? I have all the code in one template in wordpress

I'm looking at this INSERT INTO int_form_data (".implode(',',$itfkeys).") and thinking if some column name in $itfkeys needs to be enclosed in backticks then it would cause an sql error.