Get columns if no data in query

Question

I want to get the columns selected in query if no data are returned

 $sql = $this->em->getConnection()->prepare('
                SELECT
                    DATE_FORMAT(cus.period, "%Y") as ANNEE,
                    DATE_FORMAT(cus.period, "%m") as MOIS,
                    c.name AS PAYS,
                    co.id AS ORIGINE_ID,
                    co.name AS ORIGINE,
                FROM customs AS cus
                WHERE cp.product in (503)
                GROUP BY ANNEE, MOIS, PRODUCT, co.id , c.id
                ORDER BY ANNEE, MOIS, CAMPAGNE, PRODUCT, co.id, c.name;'
        );
$sql->execute();
$result = $sql->fetchAll();

I no data the result is an empty array, but I want in case that no data result should be an array like

$result = [ 'ANNEE', 'MOIS', 'PAYS', 'ORIGINE_ID', 'ORIGINE'
]

Answer 1

getConnection() in Doctrine returns the PDO it wraps which means we can use getColumnMeta() to get the column names:

$stmt = $sql->execute();
$columnNames = array();

foreach(range(0, $stmt->columnCount() - 1) as $index) {
    $columnNames[] = $stmt->getColumnMeta($index)['name'];
}

$columnNames can then be added to your $result