Check if username exists PDO - php

Question

How would I be able to check multiple factors combined instead of checking for each one? So basically I'm using PDO and I have to make sure that the usernames and emails are unique. So how would I do that? I've seen
if ( $sthandler->rowCount() > 0 ) {
// do something here
}
But is there a better way to do it. Also if there isn't can someone explain how I'd work with that.
EDIT
Here's my query code that inputs into the database
<?php
try {
$handler = new PDO('mysql:host=localhost;dbname=s','root', '*');
$handler->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e){
exit($e->getMessage());
}
$name = $_POST['name'];
$username = $_POST['username'];
$email = $_POST['email'];
$password = $_POST['password'];
$password1 = $_POST['passwordconf'];
$ip = $_SERVER['REMOTE_ADDR'];
//Verifcation
if (empty($name) || empty($username) || empty($email) || empty($password) || empty($password1))
{
echo "Complete all fields";
}
// Password match
if ($password != $password1)
{
echo $passmatch = "Passwords don't match";
}
// Email validation
if (!filter_var($email, FILTER_VALIDATE_EMAIL))
{
echo $emailvalid = "Enter a valid email";
}
// Password length
if (strlen($password) <= 6){
echo $passlength = "Choose a password longer then 6 character";
}
function userExists($db, $user)
{
$userQuery = "SELECT * FROM userinfo u WHERE u.user=:user;";
$stmt = $db->prepare($userQuery);
$stmt->execute(array(':user' => $user));
return !!$stmt->fetch(PDO::FETCH_ASSOC);
}
$user = 'userName';
$exists = userExists($db, $user);
if(exists)
{
// user exists already.
}
else
{
// user doesn't exist already, you can savely insert him.
}
if(empty($passmatch) && empty($emailvalid) && empty($passlength)) {
//Securly insert into database
$sql = 'INSERT INTO userinfo (name ,username, email, password, ip) VALUES (:name,:username,:email,:password,:ip)';
$query = $handler->prepare($sql);
$query->execute(array(
':name' => $name,
':username' => $username,
':email' => $email,
':password' => $password,
':ip' => $ip
));
}
?>

Answer 1

<?php
//Connections
try {
$handler = new PDO('mysql:host=localhost;dbname=s','root', '*');
$handler->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e){
exit($e->getMessage());
}
$name = $_POST['name'];
$username = $_POST['username'];
$email = $_POST['email'];
$password = $_POST['password'];
$password1 = $_POST['passwordconf'];
$ip = $_SERVER['REMOTE_ADDR'];
//Verifcation
if (empty($name) || empty($username) || empty($email) || empty($password) || empty($password1)){
$error = "Complete all fields";
}
// Password match
if ($password != $password1){
$error = "Passwords don't match";
}
// Email validation
if (!filter_var($email, FILTER_VALIDATE_EMAIL)){
$error = "Enter a valid email";
}
// Password length
if (strlen($password) <= 6){
$error = "Choose a password longer then 6 character";
}
if(!isset($error)){
//no error
$sthandler = $handler->prepare("SELECT username FROM users WHERE username = :name");
$sthandler->bindParam(':name', $username);
$sthandler->execute();
if($sthandler->rowCount() > 0){
echo "exists! cannot insert";
} else {
//Securly insert into database
$sql = 'INSERT INTO userinfo (name ,username, email, password, ip) VALUES (:name,:username,:email,:password,:ip)';
$query = $handler->prepare($sql);
$query->execute(array(
':name' => $name,
':username' => $username,
':email' => $email,
':password' => $password,
':ip' => $ip
));
}
}else{
echo "error occured: ".$error;
exit();
}

Answer 2

Something like this should work:
function userExists($db, $user)
{
$userQuery = "SELECT * FROM userinfo u WHERE u.user=:user;";
$stmt = $db->prepare($userQuery);
$stmt->execute(array(':user' => $user));
return !!$stmt->fetch(PDO::FETCH_ASSOC);
}
$user = 'userName';
$exists = userExists($db, $user);
if(exists)
{
// user exists already.
}
else
{
// user doesn't exist already, you can savely insert him.
}

Answer 3

The code you show has no much sense to check if username and email are unique. You should set UNIQUE KEY on the database.