为什么我的查询在 Codility 的测试编辑器上返回错误？

Question

我在 SQLite 中对Codility / 练习 6 SQL / SqlEventsDelta 的解决方案在本地数据库浏览器中有效，但在在线 Codility 测试编辑器中无效。我该如何解决这个问题？我想使用我自己的 SQLite 代码：

WITH cte1 AS
(
    SELECT *, CASE WHEN e2.event_type = e2.prev THEN 0
                 WHEN e2.event_type = e2.next THEN 0
                 ELSE 1 END AS grp
    FROM (SELECT *, LAG(e1.event_type) OVER(ORDER BY (SELECT 1)) AS prev , LEAD(e1.event_type) OVER(ORDER BY (SELECT 1)) AS next FROM events e1) e2
)
,cte2 AS
(
    SELECT cte1.event_type, cte1.time, cte1.grp, cte1.value - LAG(cte1.value) OVER(ORDER BY cte1.event_type, cte1.time) AS value
    FROM cte1
    WHERE cte1.grp = 0
    ORDER BY cte1.event_type, cte1.time
)

SELECT c2.event_type, c2.value
FROM cte2 c2
WHERE (c2.event_type, c2.time) IN (
    SELECT c2.event_type, MAX(c2.time) AS time
    FROM cte2 c2
    GROUP BY c2.event_type)
GROUP BY c2.event_type
ORDER BY c2.event_type, c2.time

它在 DB Browser for SQLite Version 3.12.2 上运行，没有错误：

event_type | value
-----------+-----------
2          | -5
3          | 4

Execution finished without errors.
Result: 2 rows returned in 7ms

但在 Codility 测试编辑器（SQLite 版本 3.11.0）上我收到错误：

| Compilation successful.

| Example test:   (example test)
| Output (stderr):
| error on query: ...
| ...
| ...,
| details: near "(": syntax error
| RUNTIME ERROR (tested program terminated with exit code 1)

Detected some errors.

Answer 1

我尝试使用一种天真的方法。我知道由于有很多子查询，这对性能非常不利，但这里的问题是 PostgreSQL 的“DISTINCT ON”，但是我得到了 100%

希望你喜欢！

select distinct on (event_type) event_type, result * -1
from (select event_type, value, lead(value) over (order by event_type) - value result
      from (select *
            from events
            where event_type in (select event_type
                                 from events
                                 group by event_type
                                 having count(event_type) >= 2)
            order by event_type, time desc) a) b