Every time i refresh page it inserts same user into database

Question

Here is PHP code

<?php
if(isset($_POST['Murad'])){
$firstname=$_POST['firstname'];
$lastname=$_POST['lastname'];
$userName=$_POST['username'];
$password=$_POST['pwd1'];
$userName = stripslashes($userName);
$password = stripslashes($password);
$email=$_POST['email'];
$mysql_hostname = "localhost";
$mysql_user = "root";
$mysql_password = "123";
$mysql_databse = "websiteusers";
$prefix = "";
$bd = mysqli_connect($mysql_hostname, $mysql_user, $mysql_password) or die("Could not connect database");
$sql = "INSERT INTO websiteusers 
       (fullname,lastname,userName,email,pass) 
       VALUES ( '$firstname', '$lastname','$userName', '$email','$password')";
        mysqli_select_db($bd,'websiteusers');
$retval = mysqli_query($bd,$sql );
if(! $retval )
{
  die('Could not enter data: ');
  return false;
}
else {echo "Entered data successfully\n";
   }

   $usernamecheck=mysqli_query($bd,"SELECT `userName` FROM `websiteusers` 
                             WHERE userName='$userName'");
if(mysqli_num_rows($usernamecheck)>=1){
   echo $userName." is already taken";
 return false;
 }header("Location: Main.php");}

?>

User registers then when he is in his profile page as soon as he refreshes it inserts same username again.And also username and email are unique in my dt it cant insert it and gives an error

you may want to look at the POST/Redirect/GET pattern, ie. http://stackoverflow.com/questions/3882149/trying-to-understand-the-post-redirect-get-design-pattern-implemented-with-php or https://en.wikipedia.org/wiki/Post/Redirect/Get — Sean, Aug 30 '15 at 05:52

DannyPhantom · Answer 1 · 2015-08-30T07:14:20.553

0

What you are doing right now is you insert a user in the DB and after that you perform a check if the user exists. You'll have to move some code around.

$bd = mysqli_connect($mysql_hostname, $mysql_user, $mysql_password) or die("Could not connect database");
 $usernamecheck=mysqli_query($bd,"SELECT `userName` FROM `websiteusers` 
                             WHERE userName='$userName'");
if(mysqli_num_rows($usernamecheck)>=1){
   echo $userName." is already taken";
 } else {
$sql = "INSERT INTO websiteusers 
       (fullname,lastname,userName,email,pass) 
       VALUES ( '$firstname', '$lastname','$userName', '$email','$password')";
        mysqli_select_db($bd,'websiteusers');
$retval = mysqli_query($bd,$sql );
if(! $retval )
{
  die('Could not enter data: ');
}
else {
    echo "Entered data successfully\n";
}
}
    }

This way you first check if the user already exists. If does - you kill the script and the code after is not executed. Otherwise you insert a user in the DB

edited Aug 30 '15 at 07:14

answered Aug 30 '15 at 05:48

DannyPhantom

1,042
10
21

it gives error in this line "if(mysqli_num_rows($usernamecheck)>=1)" – Kolibrok Aug 30 '15 at 05:53
mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in C:\AppServ\www\murad\centil\o\ch.php on line 18 – Kolibrok Aug 30 '15 at 05:57
Try changing the SELECT query to `SELECT * FROM websiteusers WHERE userName='$userName'"` – DannyPhantom Aug 30 '15 at 06:09
I added this code $result=mysqli_query($bd,$usernamecheck) or die(); and it deleted that error but now it gives mysqli_query() [function.mysqli-query]: Empty query in – Kolibrok Aug 30 '15 at 06:19
Basically that error means that the query failed. Usually this is a syntax error (which doesn't seem to be the case) or the table\column don't exist. – DannyPhantom Aug 30 '15 at 06:20
But im sure there is column like that – Kolibrok Aug 30 '15 at 06:23
change the if to `if(mysqli_num_rows($result)>=1){` – DannyPhantom Aug 30 '15 at 06:27
do an `echo mysqli_error($bd);` before the `if(mysqli_num_rows($result)>=1)` and see the result – DannyPhantom Aug 30 '15 at 06:34
Okay it deleted that error(i forgot to select dt) but guess what? new error – Kolibrok Aug 30 '15 at 06:40
You should stop saying that without specifying the error – DannyPhantom Aug 30 '15 at 06:43
I commented that in answer above but here it is mysqli_query() expects parameter 2 to be string, object given in – Kolibrok Aug 30 '15 at 06:44
Change the query back to `$usernamecheck=mysqli_query($bd,"SELECT * FROM websiteusers WHERE userName='$userName'");` – DannyPhantom Aug 30 '15 at 06:44
it always was like that.Error is about $result=mysqli_query($bd,$usernamecheck) or die(); – Kolibrok Aug 30 '15 at 06:46
Where did you put that line? – DannyPhantom Aug 30 '15 at 06:47
remove that line, change the if back to `if(mysqli_num_rows($usernamecheck)>=1)` – DannyPhantom Aug 30 '15 at 06:55
now it removed all errors but it adds username again – Kolibrok Aug 30 '15 at 07:00
instead of `echo $userName." is already taken";` do `die($userName." is already taken");` – DannyPhantom Aug 30 '15 at 07:02
There you go. Code works as expected. If you don't want the code to exit you have to play with your if - else statements, otherwise your problem should be solved – DannyPhantom Aug 30 '15 at 07:07
Same errors mysqli_query() expects parameter 1 to be mysqli, null given mysqli_num_rows() expects parameter 1 to be mysqli_result, null given mysqli_select_db() expects parameter 1 to be mysqli, null given in mysqli_query() expects parameter 1 to be mysqli, null given in – Kolibrok Aug 30 '15 at 07:19
Change the part before if to what you had when it didn't throw any errors – DannyPhantom Aug 30 '15 at 07:23

score 0 · Answer 2 · answered Aug 30 '15 at 05:57

0

What you can do is after the form has submitted successfully,

you can reset the form

or

redirect the user to the same page

if(! $retval )
{
  die('Could not enter data: ');
  return false;
}
else {
    echo "Entered data successfully\n";
     header("Location:samepagename.php");

   }

TO reset the form

      this.form.reset();

call this after form has successfully submitted

answered Aug 30 '15 at 05:57

Meenesh Jain

2,532
2
19
29

$('#full').submit(function(e){ this. FORM.reset(); console.log("submitted"); }); – Kolibrok Aug 30 '15 at 06:06
yes but call it inside php after the form has submitted and value have been inserted like this `echo ''` – Meenesh Jain Aug 30 '15 at 06:08
but this is not usually a good practice, because in the current scenario your form and the submit code is on the same page, so this can work but not when you are following some good standards for development like MVC then you only have one option is to redirect the user – Meenesh Jain Aug 30 '15 at 06:10

Rehmat · Answer 3 · 2015-08-30T06:47:23.063

Try this:

<?php
    if(isset($_POST['Murad'])) {
        $firstname=$_POST['firstname'];
        $lastname=$_POST['lastname'];
        $userName=$_POST['username'];
        $password=$_POST['pwd1'];
        $userName = stripslashes($userName);
        $password = stripslashes($password);
        $email=$_POST['email'];
        $mysql_hostname = "localhost";
        $mysql_user = "root";
        $mysql_password = "123";
        $mysql_databse = "websiteusers";
        $prefix = "";

        $link = new PDO('mysql:dbhost='.$mysql_hostname.';dbname='.$mysql_database,$mysql_user, $mysql_password);
        $unamecheck = ("SELECT userName FROM websiteusers WHERE userName = :uname");
        $unamecheck = $link->prepare($unamecheck);
        $unamecheck->execute(array(':uname'=>$userName));
        if($unamecheck->rowCount() > 0) {
            echo "Username taken";
            die();
        } else {
            $add = ("INSERT INTO websiteusers (fullname, lastname, userName, email, pass) VALUES (:fname, :lname, :uname, :pass)");
            $add = $link->prepare($add);
            $add->execute(array(':fname'=>$firstname, ':lname'=>$lastname, ':uname'=>$userName, ':pass'=>$password));
            if($add->rowCount() > 0) {
                echo "Registration successful";
                header("Location: Main.php");
            } else {
                echo "Registration failed";
            }
        }
    }
?>

mysqli_query() expects parameter 2 to be string, object given in — Kolibrok, Aug 30 '15 at 06:41
it showed bunch of errors :Uncaught exception 'PDOException' with message 'could not find driver' in C:\AppServ\www\murad\centil\o\ch.php:16 Stack trace: #0 C:\AppServ\www\murad\centil\o\ch.php(16): PDO->__construct('mysql:dbhost=lo...', 'root', '123') #1 C:\AppServ\www\murad\centil\o\Main.php(2): include('C:\AppServ\www\...') #2 {main} thrown in C:\AppServ\www\murad\centil\o\ch.php on line 16 — Kolibrok, Aug 30 '15 at 06:53

Every time i refresh page it inserts same user into database

3 Answers3