Alert box not show when sign up has same username












1















I am doing my a sign up using php, I want to show up an alert box that show "User already taken". However when I sign up an account that have same information like the last account, it's not show an alert box. It will go back to blank login page like I set it. The data duplicate not write to the mySQL but the alert box not show.
Thanks



<?php

session_start();
header('location:login.php');
$con = mysqli_connect('localhost','root','');

mysqli_select_db($con, 'userregistration');

$name = $_POST['user'];
$pass = $_POST ['password'];
$email = $_POST['mail'];
$phone = $_POST['phone'];

$s = " SELECT * FROM usertable WHERE name = '$name'";

$result = mysqli_query($con, $s);

$num = mysqli_num_rows($result);

if ($num == 1){
$message="User already taken";
echo "<script type='text/javascript'> alert('$message');</script>";
}else {
$reg = "INSERT INTO usertable(name, password, email, phone ) values ('$name', '$pass','$email', '$phone')";/*, '$email','$phone'*/
mysqli_query($con, $reg);
echo"Registration successfull";
}
?>









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  • 1





    In case you prevented the page from showing more alerts, try appending your message after your script tag and see if the message shows up. Also, your code is vulnerable to SQL injections

    – Thum Choon Tat
    Nov 22 '18 at 3:37
















1















I am doing my a sign up using php, I want to show up an alert box that show "User already taken". However when I sign up an account that have same information like the last account, it's not show an alert box. It will go back to blank login page like I set it. The data duplicate not write to the mySQL but the alert box not show.
Thanks



<?php

session_start();
header('location:login.php');
$con = mysqli_connect('localhost','root','');

mysqli_select_db($con, 'userregistration');

$name = $_POST['user'];
$pass = $_POST ['password'];
$email = $_POST['mail'];
$phone = $_POST['phone'];

$s = " SELECT * FROM usertable WHERE name = '$name'";

$result = mysqli_query($con, $s);

$num = mysqli_num_rows($result);

if ($num == 1){
$message="User already taken";
echo "<script type='text/javascript'> alert('$message');</script>";
}else {
$reg = "INSERT INTO usertable(name, password, email, phone ) values ('$name', '$pass','$email', '$phone')";/*, '$email','$phone'*/
mysqli_query($con, $reg);
echo"Registration successfull";
}
?>









share|improve this question


















  • 1





    In case you prevented the page from showing more alerts, try appending your message after your script tag and see if the message shows up. Also, your code is vulnerable to SQL injections

    – Thum Choon Tat
    Nov 22 '18 at 3:37














1












1








1








I am doing my a sign up using php, I want to show up an alert box that show "User already taken". However when I sign up an account that have same information like the last account, it's not show an alert box. It will go back to blank login page like I set it. The data duplicate not write to the mySQL but the alert box not show.
Thanks



<?php

session_start();
header('location:login.php');
$con = mysqli_connect('localhost','root','');

mysqli_select_db($con, 'userregistration');

$name = $_POST['user'];
$pass = $_POST ['password'];
$email = $_POST['mail'];
$phone = $_POST['phone'];

$s = " SELECT * FROM usertable WHERE name = '$name'";

$result = mysqli_query($con, $s);

$num = mysqli_num_rows($result);

if ($num == 1){
$message="User already taken";
echo "<script type='text/javascript'> alert('$message');</script>";
}else {
$reg = "INSERT INTO usertable(name, password, email, phone ) values ('$name', '$pass','$email', '$phone')";/*, '$email','$phone'*/
mysqli_query($con, $reg);
echo"Registration successfull";
}
?>









share|improve this question














I am doing my a sign up using php, I want to show up an alert box that show "User already taken". However when I sign up an account that have same information like the last account, it's not show an alert box. It will go back to blank login page like I set it. The data duplicate not write to the mySQL but the alert box not show.
Thanks



<?php

session_start();
header('location:login.php');
$con = mysqli_connect('localhost','root','');

mysqli_select_db($con, 'userregistration');

$name = $_POST['user'];
$pass = $_POST ['password'];
$email = $_POST['mail'];
$phone = $_POST['phone'];

$s = " SELECT * FROM usertable WHERE name = '$name'";

$result = mysqli_query($con, $s);

$num = mysqli_num_rows($result);

if ($num == 1){
$message="User already taken";
echo "<script type='text/javascript'> alert('$message');</script>";
}else {
$reg = "INSERT INTO usertable(name, password, email, phone ) values ('$name', '$pass','$email', '$phone')";/*, '$email','$phone'*/
mysqli_query($con, $reg);
echo"Registration successfull";
}
?>






php html






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asked Nov 22 '18 at 3:16









beam291beam291

147




147








  • 1





    In case you prevented the page from showing more alerts, try appending your message after your script tag and see if the message shows up. Also, your code is vulnerable to SQL injections

    – Thum Choon Tat
    Nov 22 '18 at 3:37














  • 1





    In case you prevented the page from showing more alerts, try appending your message after your script tag and see if the message shows up. Also, your code is vulnerable to SQL injections

    – Thum Choon Tat
    Nov 22 '18 at 3:37








1




1





In case you prevented the page from showing more alerts, try appending your message after your script tag and see if the message shows up. Also, your code is vulnerable to SQL injections

– Thum Choon Tat
Nov 22 '18 at 3:37





In case you prevented the page from showing more alerts, try appending your message after your script tag and see if the message shows up. Also, your code is vulnerable to SQL injections

– Thum Choon Tat
Nov 22 '18 at 3:37












1 Answer
1






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oldest

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You may need to check for successful connection/query first:



if($result=mysqli_query($con,$s)) {
if(mysqli_num_rows($result)==1) {
... user already taken code ...
} else {
... insert new user code ...
}
}


See w3schools ref: https://www.w3schools.com/php/func_mysqli_num_rows.asp



This may also help you debug where the problem is occurring.






share|improve this answer























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    0














    You may need to check for successful connection/query first:



    if($result=mysqli_query($con,$s)) {
    if(mysqli_num_rows($result)==1) {
    ... user already taken code ...
    } else {
    ... insert new user code ...
    }
    }


    See w3schools ref: https://www.w3schools.com/php/func_mysqli_num_rows.asp



    This may also help you debug where the problem is occurring.






    share|improve this answer




























      0














      You may need to check for successful connection/query first:



      if($result=mysqli_query($con,$s)) {
      if(mysqli_num_rows($result)==1) {
      ... user already taken code ...
      } else {
      ... insert new user code ...
      }
      }


      See w3schools ref: https://www.w3schools.com/php/func_mysqli_num_rows.asp



      This may also help you debug where the problem is occurring.






      share|improve this answer


























        0












        0








        0







        You may need to check for successful connection/query first:



        if($result=mysqli_query($con,$s)) {
        if(mysqli_num_rows($result)==1) {
        ... user already taken code ...
        } else {
        ... insert new user code ...
        }
        }


        See w3schools ref: https://www.w3schools.com/php/func_mysqli_num_rows.asp



        This may also help you debug where the problem is occurring.






        share|improve this answer













        You may need to check for successful connection/query first:



        if($result=mysqli_query($con,$s)) {
        if(mysqli_num_rows($result)==1) {
        ... user already taken code ...
        } else {
        ... insert new user code ...
        }
        }


        See w3schools ref: https://www.w3schools.com/php/func_mysqli_num_rows.asp



        This may also help you debug where the problem is occurring.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 22 '18 at 3:31









        SparebrainSparebrain

        106110




        106110
































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