How to know which entry is duplicated? (For example username + email) - php

Question

I would like to know if it is possible to get the column name that made the duplicate error on an INSERT ?
For example, with an unique key on username and another unique key on email :
try{
$pdo->query("INSERT INTO `table`(`username`,`email`)`VALUES('Superman','xxx#xx.com')");
} catch (PDOException $e) {
if($e->errorInfo[0] == '23000' && $e->errorInfo[1] == '1062'){
throw new CustomException("Bla bla already exists");
// How does we get the duplicated column and then display "Email already exists" or "Username already exist"
} else {
throw $e;
}
}
How does we get the duplicated column info and then display "Email already exists" or "Username already exist" instead of "Duplicate entry (ok but which one?)
Thank you,

Answer 1

You can check value in db or grab colum name in the error message for your users.
try{
$pdo->query("INSERT INTO `table`(`username`,`email`) VALUES ('Superman','xxx#xx.com')");
} catch (PDOException $e) {
if (preg_match("/Duplicate entry .+ for key '(.+)'/", $e->getMessage(), $matches)) {
throw new CustomException($matches[1]." already exist");
} else {
throw $e;
}
}
also maybe you prefer to use exec command for "non result query string".
$affectedRow = $pdo->exec("INSERT INTO `table`(`username`,`email`) VALUES ('Superman','xxx#xx.com')");

Answer 2

Thanks for the idea. Didnt think that error could give me this info.
So it will result as this :
try {
$query = $this->dbh->prepare('INSERT INTO users (username,email) VALUES ("test", "test")');
$result = $query->execute();
} catch (PDOException $e) {
if( $e->errorInfo[0] == '23000' && $e->errorInfo[1] == '1062' ){
if( strpos($e->getMessage(), 'username') == true ) $result = 'duplicate_username';
elseif( strpos($e->getMessage(), 'email') == true ) $result = 'duplicate_email';
} else {
throw $e;
$return = false;
}
}
Basically doing the job.
Thanks,