PDO - get result of COUNT (*)?

Question

During the new user registration process, I try to find out if the username or email address of the user is in db. To do this, I want to find the number of rows in which the identifier (email address or username) matches the records in the database. If I haven't messed up, the only possible return values ​​are 0 or 1. My function is lower, but I need help to complete it.

function checkUserExists($userIdentifier, $tableColName){
 $dbConnection=$this->dbInstance->createConnexion();
 $query=$dbConnection->prepare("SELECT count(*) FROM users WHERE ".$tableColName."= :userIdentifier");
 $query->bindParam(":userIdentifier", $userIdentifier);
 $result=$query->execute();
 if( ????? >0){
  $return false;
 } else return true;
}

Stupid from me, I'm not sure how to get this account number. I suppose this is a variation $query->fetch(), but will it be an array on the right?

Answer 1

->fetchColumn(0), 1 ( ) .

if ( $query->fetchColumn(0) > 0 ){
  return false;
} else return true;

Answer 2

(: , PHP , , #/Java)

, $query->fetchColumn();

, 0.