foreach数据不在数据库中更新

In my local server this script works fine. When I upload this script on live it does not work properly.

It inserts only 126 rows of data into the database, but I need to upload at least 500 rows at a time.

<?php
include 'database-config.php';
foreach($_POST['classroll'] as $row=>$classroll)
{
    $sclassroll = $classroll; 
    $mark = $_POST['mark'][$row];
    $type = $_POST['rtype'];
    $session = $_POST['rsession'];
    $department = $_POST['rdepartment'];
    $examtype = $_POST['rextype'];
    $examyear = $_POST['rexyear'];
    $examsubject = $_POST['rexmarksubject'];

$stmt = $dbh->prepare("INSERT INTO exammarks(studnettype, studentsession, studentdepartment, studentclassroll, examtype, examyear, examsubjec, exammarks) VALUES (:studnettype, :studentsession, :studentdepartment, :studentclassroll, :examtype, :examyear, :examsubjec, :exammarks)");

  $stmt->bindParam('studnettype', $type);
  $stmt->bindParam('studentsession', $session);
  $stmt->bindParam('studentdepartment', $department);
  $stmt->bindParam('studentclassroll', $sclassroll);
  $stmt->bindParam('examtype', $examtype);
  $stmt->bindParam('examyear', $examyear);
  $stmt->bindParam('examsubjec', $examsubject);
  $stmt->bindParam('exammarks', $mark);


$stmt->execute();
}
header('Location: ../home.php');
?>

It is possible that your exammarks table definition on your live server contains a unique index that is not present on your local host server. If that were true some of your INSERT operations might fail.

The code you showed us doesn't check for errors. Obviously, when your program deals with high value data (such as the results of student examinations) you should check for errors.

Try this instead:

if( !$stmt->execute()) {
    print_r( $arr = $stmt->errorInfo() );
}
else {
    /* INSERT statement completed correctly */
}