invalid parameter number exception using named parameter - php

Question

I am getting "invalid parameter number:parameter undefined" exception when attempting an insert query to mysql database.
I am returning the result to my Android app as json.
if (!empty($_POST))
{
$query = "INSERT INTO attendance (tdate,slot_from,slot_to,coursecode,stud_id,remark) VALUES (:dat,:fromm,:too,:ccode,:stud,:rmk ) ";
$query_params = array(
':dat' => $_POST['datee'],
':from'=>$_POST['fromm'],
':to'=>$_POST['too'],
':ccode'=>$_POST['course'],
':stud'=>$_POST['sname'],
':rmk'=>$_POST['remark'],
);
try
{
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch (PDOException $ex)
{
//or just use this use this one to product JSON data:
$response["success"] = 0;
$response["message"] = $ex->getMessage();
$response["date"] = $_POST['datee'];
$response["from"] = $_POST['fromm'];
$response["to"] = $_POST['too'];
$response["ccode"] = $_POST['course'];
$response["stud"] = $_POST['sname'];
$response["remark"] = $_POST['remark'];
die(json_encode($response));
}
}

Answer 1

you lack a m in
':from'=>$_POST['fromm'],
should be
':fromm'=>$_POST['fromm'],
you must be careful when using named parameter, I myself am very prone to making such errors
that's why I more easily use the ? placeholder, this way in your exemple:
$query = "INSERT INTO attendance (tdate,slot_from,slot_to,coursecode,stud_id,remark) VALUES (?,?,?,?,?,?) ";
$query_params = array(
$_POST['datee'],
$_POST['fromm'],
$_POST['too'],
$_POST['course'],
$_POST['sname'],
$_POST['remark'],
);
then:
$result = $stmt->execute($query_params);
you must be sure that the params are in good order (same as in query)

Answer 2

In your query, you're misspelling from:
$query = "INSERT INTO attendance (tdate,slot_from,slot_to,coursecode,stud_id,remark) VALUES (:dat,:fromm,:too,:ccode,:stud,:rmk ) ";
Replace it with:
$query = "INSERT INTO attendance (tdate,slot_from,slot_to,coursecode,stud_id,remark) VALUES (:dat,:from,:too,:ccode,:stud,:rmk ) ";