PDO UNION function only processes first SELECT statement - mysql

Question

Okay so I have three different types of users (Developers, Designers & Employers) all of whom have different database tables. I have successfully developed a script that can log in a user from any of the three user tables using UNION. However I have now introduced email verification on sign up so I need to test whether the 'confirmed' field (in each table) has a value of '1' to process a successful login (if the value is 0, the user will not be able to log in).
public function email_confirmed($email) {
$query = $this->db->prepare("SELECT
COUNT(developers.id) FROM " . DB_NAME . ".developers WHERE developers.email= ? AND developers.confirmed = ?
UNION SELECT COUNT(designers.id) FROM " . DB_NAME . ".designers WHERE designers.email = ? AND designers.confirmed = ?
UNION SELECT COUNT(employers.id) FROM " . DB_NAME . ".employers WHERE employers.email = ? AND employers.confirmed = ?
");
$query->bindValue(1, $email);
$query->bindValue(2, 1);
$query->bindValue(3, $email);
$query->bindValue(4, 1);
$query->bindValue(5, $email);
$query->bindValue(6, 1);
try{
$query->execute();
$rows = $query->fetchColumn();
if($rows == 1){
return true;
}else{
return false;
}
} catch(PDOException $e){
die($e->getMessage());
}
}
At the moment however (using the function below), only a developer can log in. If you attempt to log in using a designer or an employer account, the error below shows. Any ideas why this is happening?
if ($users->email_confirmed($email) === false) {
$errors[] = 'Sorry, but you need to activate your account. Please check your emails.';
} else // carry on logging in user

Answer 1

This is your query:
SELECT COUNT(developers.id)
FROM " . DB_NAME . ".developers
WHERE developers.email= ? AND developers.confirmed = ?
UNION
SELECT COUNT(designers.id)
FROM " . DB_NAME . ".designers
WHERE designers.email = ? AND designers.confirmed = ?
UNION
SELECT COUNT(employers.id)
FROM " . DB_NAME . ".employers
WHERE employers.email = ? AND employers.confirmed = ?
It is fetching three rows, then removing duplicates, and ordering them arbitrarily. You are then reading the value (the count) from one of these rows.
Taking the approach you are taking, I think you want:
select COUNT(*)
from ((select 1
from " . DB_NAME . ".developers
where developers.email= ? AND developers.confirmed = ?
) union all
(select 1
from " . DB_NAME . ".designers
where designers.email = ? AND designers.confirmed = ?
) union all
(select 1
from " . DB_NAME . ".employers
where employers.email = ? AND employers.confirmed = ?
)
) t