SQL多表合并查询结果

两表合并查询，并同时展示及分页

SELECT
    a.*
FROM
    (
        (
            SELECT
                punycode,
                `domain`,
                'Success' AS state,
                add_time,
                0 AS refund_status,
                icp,
                icp_state,
                1 AS order_id
            FROM
                exp_dnbiz_user_domains
            WHERE
                user_id = 8
            AND punycode = 'shang.com'
        )
        UNION ALL
            (
                SELECT
                    punycode,
                    `domain`,
                    state,
                    add_time,
                    refund_status,
                    'icp_state' AS icp_state,
                    'icp' AS icp,
                    order_id
                FROM
                    exp_dnbiz_user_domain_transfer
                WHERE
                    (
                        state = 'Pending'
                        OR (
                            state = 'Failure'
                            AND refund_status < 2
                        )
                    )
                AND user_id = 8
                AND punycode = 'shang.com'
            )
    ) AS a
ORDER BY
    add_time DESC
LIMIT 0,
 10