User name already exist in this case what have problem no show message

[Raghvendra_Srivastav]

if(isset($_POST['save']))
{
$query = mysql_query("SELECT*FROM user WHERE user_name");
if (mysql_num_rows($query)>1)
{
echo 'User name have table';
}
else {
  mysql_query("INSERT INTO `user` ( `user_id`,`user_name`,`password`,`fullname`,`email`,`area`,`region`,`type`,`grade`,`expences`,`join_date`,`leave_date`,`comp_id`,`status`,`permission` ,`department`,`address`,`contact_no`,`distric`  ) VALUES ('', '".$_POST['user_name']."', md5('".$_POST ['password']."'),'".$_POST['fullname']."','".$_POST['email']."','".$_POST['area']."','".$_POST['region']."','".$_POST['type']."','".$_POST['grade']."','".$_POST['expences']."','".$_POST['join_date']."','".$_POST['leave_date']."','".$_POST['comp_id']."','".$_POST['status']."','".$_POST['permission']."','".$_POST['department']."','".$_POST['address']."','".$_POST['contact_no']."','".$_POST['distric']."')") ;
  echo "<META http-equiv='refresh' content='0;URL=index.php?show=user'>";
  exit;
}
}

else
{
   $msg = '&nbsp;';
}

[DaveMaxwell]

@Raghvendra_Srivastav

$query = mysql_query(“SELECT*FROM user WHERE user_name”);

Just to start with, this line is not complete. You would need something like this (note: I converted it to PDO, which is safer but requires you to change your connection):

$stmt = $pdo->prepare('SELECT user_name FROM user WHERE user_name = :name');
$stmt->execute(array('name' => $_POST['user_name']));
if ($stmt->rowCount() > 1) {
    echo 'User name have table';
} else {
    // you'll need to do something similar for your insert statement....
}

[r937]

by doing a SELECT first, before the INSERT, without locking the two statements with a transaction, you leave yourself open to a race condition

if you want a simple solution, forget the SELECT and use the ON DUPLICATE KEY option of the INSERT statement