[WordPress]get_post_by_post_name

public function get_post_by_post_name($post_name, $post_type = '', $post_status = 'publish')
{
    global $wpdb;
    $sql = array();
    $sql[] = "SELECT p.*";
    $sql[] = "FROM $wpdb->posts AS p";
    $sql[] = "WHERE p.post_name " . $this->__get_sql_for_in($post_name);
    if (!empty($post_type))
        $sql[] = "AND p.post_type = '$post_type'";
    if(!empty($post_status))
        $sql[] = "AND p.post_status = '$post_status'";
    $result = $wpdb->get_results(implode(' ', $sql));
    if (empty($result))
        return null;
    return is_array($post_name) ? $result : $result[0];
}
protected function __get_sql_for_in($values, $is_number = false)
{
    $quote    = $is_number ? "" : "'";
    $is_array = is_array($values);
    $not      = ($is_array && is_string($values[0]) && preg_match('/^.*\!=.+$/',$values[0])) || (!$is_array && is_string($values) && preg_match('/^.*\!=.+$/',$values));
    $in       = $not ? ' NOT IN' : ' IN';
    $eq       = $not ? '!=' : '=';
    if($is_array){
        foreach ($values as $i => $value) {
            $values[$i] = preg_replace('/^(\!=|=)/', '', esc_sql($value));
            $values[$i] = preg_replace('/^ /', '', esc_sql($value));
        }
    }else{
        $values = preg_replace('/^(\!=|=)/','',esc_sql($values));
        $values = preg_replace('/^ /','',esc_sql($values));
    }
    return $is_array && 1 < count($values) ? "{$in} ({$quote}" . implode("{$quote},{$quote}", $values) . "{$quote})" : ($is_array ? "{$eq} {$quote}{$values[0]}{$quote}" : "{$eq} {$quote}$values{$quote}");
}