class ModifyDBAirlineInfoChangeKeys extends T32Migration
{


    public function run()
    {

        $sql = "ALTER TABLE `dbairlineinfo` DROP PRIMARY KEY";
        try {
            mysql_query($sql);
        } catch (Exception $ex) {
            return $ex->getMessage();
        }
        $sql = "ALTER TABLE `dbairlineinfo` ADD `id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY FIRST;";
        try {
            mysql_query($sql);
        } catch (Exception $ex) {
            return $ex->getMessage();
        }
        try {
            $sql = "CREATE UNIQUE u_iata_codes ON `dbairlineinfo`(`iata`,`bookingclasscodes`);";
            mysql_query($sql);
        } catch (Exception $ex) {
            return $ex->getMessage();
        }
        return true;
    }
}