/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

0 vote375 views1 answer
Password change logout from wordpress
PHP Wordpress
2 votes428 views3 answers
Get request uri from request laravel 7
PHP Laravel
5 votes370 views2 answers
Set unique value validation for laravel form request
PHP Laravel
0 vote332 views1 answer
Alter mysql 8 user root phpmyadmin first install
PHP
0 vote330 views1 answer
Laravel optional params
PHP
1 vote390 views1 answer
[InvalidArgumentException] Could not find package laravel/laravel with version 7.0 in a version installable using your PHP version, PHP extensions and Composer version.
PHP Laravel
32 votes318 views6 answers
Php implode array
PHP
0 vote314 views1 answer
What is carriage return in php
PHP
0 vote398 views1 answer
<warning>PHP Warning: preg_grep() expects parameter 2 to be array, string given in G:\Office Projects\Luggage Backend\vendor\laravel\framework\src\Illuminate\Database\Eloquent\Concerns \Guards Attributes.php on line 207</warning>
PHP Laravel
0 vote357 views1 answer
Wp custom rest endpoint
PHP