尝试使用LAG（）窗口函数执行以下操作：

SELECT *
FROM (
    SELECT *, LAG(event) OVER (PARTITION BY user ORDER BY timecreated) AS prev_event
    FROM log
) t
WHERE event = 'open'
AND prev_event = 'login'
AND context = 5

如果您使用的是MySQL〈8，您可以用途：

SELECT o.*
FROM log o
JOIN log l
    ON l.event = 'login'
    AND o.user = l.user
    AND o.timecreated > l.timecreated
WHERE o.event = 'open'
AND o.context = 5
AND NOT EXISTS (
    SELECT 1 FROM log
    WHERE user = o.user
    AND timecreated > l.timecreated
    AND timecreated < o.timecreated
);

最好使用id进行事件顺序比较，但id和timecreated值不同步。在示例中，5、8和13出现在所有其他具有更高ID的行之后。这可能是创建示例时的错误。

select * from test t
where t.event = 'open' and
    t.user =
   (select user
    from test
    where id = (select max(id) from test where  id < t.id) and event = 'login');