While loop to check email exist in DB PHP

Question

My code is not working i want to check Email exist in db or show message email exit or not when click tab button:

HTML:

<input class="form-control" type="text"  name="email" id="email" onkeyup="checkemail();" required>```

PHP:

<?php
    $checkemail = mysqli_query($conn, "Select email FROM users WHERE email = '$email'")
    while(mysqli_fetch_assoc($checkemail) > 0)
         {
          echo "Email Already Exist :)";
         }
         else
         {
          echo "OK  :)";
         }
        exit();
        }
?>

`mysqli_fetch_assoc` doesn't return an integer. You should first prevent SQL injections, `Select count(*) FROM users WHERE email = ?` (and just get a count). Then execute, check the return and output based on that. — user3783243, Aug 25 '20 at 13:40
Use `mysqli_num_rows($checkemail) ` instead of `mysqli_fetch_assoc($checkemail)`. Try This — Vinayak, Aug 25 '20 at 13:41
You need to check if it's `NULL`. See [here](https://www.php.net/manual/en/mysqli-result.fetch-assoc.php) for more. — Vasilis G., Aug 25 '20 at 13:41

score 0 · Answer 1 · answered Aug 25 '20 at 13:41

0

You need to check num_row like that:

 $checkemail = $conn->prepare("Select email FROM users WHERE email = ?");
 $checkemail->bind_param('s',$email);
 $checkmail->execute();
 $result = $checkmail->get_result();
 if ($result->num_rows > 0) {
   echo 'mail exist'; exit();
  }else{
  echo "mail doesn't exist";
  }

i change part of the code for improve security

answered Aug 25 '20 at 13:41

Simone Rossaini

8,115
1
13
34

What is the point in selecting the values if you do not use them? – Dharman Aug 25 '20 at 14:13
@Dharman for check if email exist or not you must select it no? – Simone Rossaini Aug 26 '20 at 06:29

Vinayak · Answer 2 · 2020-08-25T20:16:16.603

-1

Use mysqli_num_rows($checkemail) instead of mysqli_fetch_assoc($checkemail)

Because mysqli_fetch_assoc($checkemail) does not return a integer. It returns an associative array.

$checkemail = mysqli_query($conn, "Select email FROM users WHERE email = '$email'")
        
         if(mysqli_num_rows($checkemail) > 0)
             {
              echo "Email Already Exist :)";
             }
             else
             {
              echo "OK  :)";
             }
            exit();
            }
        
        
        ?>

edited Aug 25 '20 at 20:16

answered Aug 25 '20 at 13:42

Vinayak

80
8

Parse error: syntax error, unexpected 'while' (T_WHILE) ....There some error in here?? – Khurram Aug 25 '20 at 17:32
Corrected. Now it should work – Vinayak Aug 25 '20 at 20:16

While loop to check email exist in DB PHP

2 Answers2