我如何使用MySQL5.6.43在不创建视图的情况下使下面的代码工作呢？

DROP VIEW IF EXISTS sla_calculation;
CREATE VIEW sla_calculation AS SELECT clock FROM service_alarms WHERE (serviceid = 473) AND
        (clock >= get_unix_init_clock(30, 'day'));


SELECT sla1.clock - sla2.clock AS failure_time
FROM sla_calculation AS sla1
LEFT JOIN sla_calculation AS sla2
    ON sla2.clock = (
        SELECT MAX(clock)
        FROM sla_calculation AS sla3
        WHERE sla3.clock < sla1.clock
    )
ORDER BY sla1.clock

我不想创建视图，因为这个查询将位于函数内部（更不用说它将在中包含变量，其中）。 我尝试了以下查询，但未成功（收到错误代码1146:表'test.sla1'不存在):

SELECT sla1.clock - sla2.clock AS failure_time
FROM
    (
        SELECT clock
        FROM service_alarms
        WHERE (serviceid = 473) AND
            (clock >= get_unix_init_clock(30, 'day'))
    ) AS sla1
    LEFT JOIN sla1 AS sla2
        ON sla2.clock = (
            SELECT MAX(clock)
            FROM sla1 AS sla3
            WHERE sla3.clock < sla1.clock
        )
ORDER BY sla1.clock

我知道我不能在from子句中使用别名，那么如何解决这个问题呢？ 多谢！