Log in cant find error - php

Question

Hi i am trying to create a very simple log in function using PHP however, after going through the codes, my form seem to be able to perform the function right only when i enter the right user name and password however, if i dont, it doesnt perform its duties here are my codes that i have simplified :
login.php
<form name="userlogin" action="phpprocess/loginprocess.php" method="POST">
<p>Username : <input type="text" id="username" name="username"></p>
<p>Password : <input type="password" id="password" name="password"></p>
<p><input type="submit" id="loginbtn" value="login" ></p>
</form>
loginproccess.php
include "mysqli.connect.php";
$username = $mysqli->real_escape_string($_REQUEST["username"]);
$password = $mysqli->real_escape_string($_REQUEST["password"]);
echo "$username";
echo "$password";
$sql = "select * from users.userlogin where username ='".$username."' and
password = '".$password."'";
$result = $mysqli->query($sql);
if($result == null){
echo"null";
}
if($mysqli -> errno){
error_log($mysqli -> error);
echo $mysqli -> error;
echo " hello";
exit();
}else{
while( list($index, $user1, $pass1) = $result -> fetch_array()){
if($user1 != null && $pass1 != null){
echo "$index $user1, $pass1";
}
}
}
$mysqli->close();
mysqli.connect.php
$host="localhost";
$user="root";
$password="";
$database="users";
$mysqli = new mysqli($host, $user, $password, $database);
if ($mysqli->errno) {
echo "Unable to connect to the database: <br />".$mysqli->error;
exit();
}
what happens is if i enter the wrong user name and password i need the webpage to echo hello , if i enter it right i need it to echo the right user and pass but when enter wrongly, $result does not seem to be null as null and hello is not being printed out. My error log does not display anything. Hope to hear your advice! Thank you in advance !

Answer 1

You print hello when the query gets an error, but it's not an error if the WHERE conditions don't match any rows. It just returns an empty result set. You should use:
if ($result->num_rows == 0) {
echo "hello";
exit();
}
Also, $result->fetch_array() returns an array with both numbered and named indexes. If your table has 3 columns, this will return an array with 6 elements, but you're only assigning to 3 variables.
Use $result->fetch_row() to get an array with just the numbered elements. Also, you shouldn't use SELECT * if you're relying on the order of elements like this, since that depends on the order that the columns were assigned in the CREATE TABLE statement, and this might change if you update your schema. You should list the specific columns you need in the SELECT list.