Query Checking for Existence - PHP - php

Question

I'm trying to to test to see if an email address exists in my database by running a query check.
I can connect to the database fine.
However no matter what, even if the email exists it returns "doesn't exist".
<?php
//----------------------------------------------------------------------------------//
//Setup
require_once('SB_Constants.php');
//----------------------------------------------------------------------------------//
//Connect to the database
//----------------------------------------------------------------------------------//
$connection = mysqli_connect(DATABASE_HOST, SAVE_USERNAME, SAVE_PASSWORD, DATABASE_NAME);
// check the connection was successful
if (mysqli_connect_errno($connection)) {
header('HTTP/1.0 500 Internal Server Error', true, 500);
die(FailedToAccessDatabase . ". Failed to connect to Database");
} else {
echo "Connection Success!";
}
//Query Check
$assessorEmail = mysqli_query($connection, "SELECT email_address FROM assessorID WHERE email_address = 'ryan#ablah.com'");
if (mysqli_num_rows($query_identifier) == 0) {
die(UnregisteredAssessor . ". Doesn't Exist");
} else {
// Exists
echo "Exists getting ace id.";
//Get the assessor ID
$result = mysqli_query($connection, "SELECT ace_id FROM assessorID WHERE email_address = 'ryan#blah.com'");
echo $result;
}
/* close connection */
mysqli_close($connection);
?>
Any ideas of the problem? :)

Answer 1

Various mistakes. Fix:
$assessorEmail = mysqli_query($connection, "SELECT ace_id,email_address FROM assessorID WHERE email_address = 'ryan#ablah.com'");
if (mysqli_num_rows($assessorEmail) == 0) {
die(UnregisteredAssessor . ". Doesn't Exist");
} else {
// Exists
echo "Exists getting ace id.";
//Get the assessor ID
$result = mysqli_fetch_assoc($assessorEmail);
echo $result['ace_id'];
}

Answer 2

Your problem is mysqli_num_rows($query_identifier) is accessing an undefined variable instead of $assessorEmail.
Additionally, you only need one query if you just want the ace_id:
$assessorEmail = mysqli_query($connection, "SELECT ace_id FROM assessorID WHERE email_address = 'ryan#ablah.com'");
If mysqli_num_rows($assessorEmail) returns a row, than the email exists and you already have the ace_id
while(mysqli_fetch_assoc($assessorEmail) = $row) {
echo $result['ace_id'];
}