无法插入Mysql数据库

Question

我真的很沮丧，因为我不知道我的代码中的问题是什么。在我编辑之前它工作正常，我可以将数据插入数据库但是当我添加一些它突然没有工作。然后我退回原来的代码然后它已经没有工作了。你能来看看这里的问题

upload.php的

<?php




// array for JSON response
$response = array();

// check for required fields
if (isset($_POST['agent']) && isset($_POST['days']) && isset($_POST['barcode']) && isset($_POST['client'])
&& isset($_POST['qty']) && isset($_POST['uom']) && isset($_POST['amt']) && isset($_POST['ext'])) {


$agent = $_POST['agent'];
$days = $_POST['days'];
$barcode = $_POST['barcode'];
$client = $_POST['client'];
$qty = $_POST['qty'];
$uom = $_POST['uom'];
$amt = $_POST['amt'];
$ext = $_POST['ext'];   
//$date = $_POST['date'];   

// include db connect class
require_once __DIR__ . '/dbconnect.php';

// connecting to db
$db = new DB_CONNECT();

// mysql update row with matched pid
$result = mysql_query("INSERT INTO salestrans (agent,days,barcode,client,qty,uom,amt,ext) values
('$agent','$days','$barcode','$client','$qty','$uom','$amt','$ext')");

// check if row inserted or not
if ($result) {
    // successfully updated
    $response["success"] = 1;
    $response["message"] = "Product successfully uploaded.";

    // echoing JSON response
    echo json_encode($response);
} else {

 // not successfully updated
    $response["success"] = 0;
    $response["message"] = "Product unsuccessfully uploaded.";

    // echoing JSON response
    echo json_encode($response);

}
} else {
    // required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";

// echoing JSON response
echo json_encode($response);
}
?>