/**
* @return bool|null
*/
public function exists()
{
$sql = $this->grammar->compileExists($this);
$results = $this->connection->select($sql, $this->getBindings(), !$this->useWritePdo);
if (isset($results[0])) {
$results = (array) $results[0];
return (bool) $results['exists'];
}
}
