/PHP/How to check if username already exists in php

How to check if username already exists in php

$firstname = $_POST["firstname"];
$lastname = $_POST["lastname"];
$email = $_POST["email"];
$pass = $_POST["password"];

$check_email = mysqli_query($conn, "SELECT Email FROM crud where Email = '$email' ");
if(mysqli_num_rows($check_email) > 0){
    echo('Email Already exists');
}
else{
    if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $result = mysqli_query($conn, "INSERT INTO crud (Firstname, Lastname, Email, Password) VALUES ('$firstname', '$lastname', '$email', '$pass')");
}
    echo('Record Entered Successfully');
}

Source: stackoverflow.com

How to check user already exists in php

$sql = "SELECT username FROM table_name WHERE username='{$username}'";
$result = mysqli_query($con,$sql) or die("Query unsuccessful") ;
      if (mysqli_num_rows($result) > 0) {
        echo "Username is already exist";
      } else {
             ...............   
      }

Similar codes

1 vote138 views3 answers
Queue jobs in laravel
PHP
3 votes154 views3 answers
Laravel get a url using name
PHP Laravel
3 votes133 views3 answers
Convert stdclass object to array php
PHP
21 votes147 views4 answers
How to host a php server
PHP
0 vote143 views1 answer
Woocommerce pagination
PHP
0 vote163 views2 answers
Get http host laravel
PHP Laravel
0 vote267 views1 answer
Symfony request get all parameters
PHP Symfony
0 vote136 views1 answer
Get where different laravel
PHP
3 votes136 views4 answers
Class 'App\Http\Controllers\Response' not found
PHP
0 vote154 views1 answer
Artisan call migrate result
PHP