合并MySQL SELECT语句

Question

我有下表tbl_crps，请注意，列[[crp多次出现，但是id和starts_on在具有相同 crp。

id |  crp | starts_on  |
------------------
1  |  20  | 2020-02-09 |
2  |  31  | 2019-06-05 |
3  |  20  | 2018-01-10 |
4  |  31  | 2021-07-03 |
5  |  58  | 2022-01-01 |
6  |  58  | 2025-02-02 |

我需要在以下情况下提取记录：
如果是
crp

，则存在一个或多个具有过去starts_on的记录，那么在那些具有crp的记录（具有过去日期的记录）中，具有最大id的记录必须是返回

如果用于

crp

，则没有过去日期的记录，则在所有具有该[[crp]的记录中，具有最大ID的记录我可以成功选择符合以下条件的第一个条件的记录。

SELECT * FROM tbl_crps 
AND id IN (SELECT MAX(b.id) FROM tbl_crps b WHERE b.starts_on <= "2020-10-02")

将返回ID为3和2的记录。

我需要实现的是将结果[不在过去，而

crp

不在第一个结果集中的那些记录添加到结果中。

有可能吗？也许是这样吗？

SELECT * FROM tbl_crps a
WHERE id IN (
     SELECT MAX(a.id) FROM tbl_crps a WHERE a.starts_on <= "2020-10-02"
 )
UNION
(
    SELECT * FROM tbl_crps b
        WHERE id IN (
             SELECT MAX(c.id) FROM tbl_crps c WHERE c.starts_on > "2020-10-02"
             AND c.crp NOT IN (
                  SELECT d.crp FROM tbl_crps d
                  WHERE id IN (
                       SELECT MAX(e.id) FROM tbl_crps e WHERE e.starts_on <= "2020-10-02")
                   )
        )
)

我有下表tbl_crps，请注意，列crp出现了不止一次，但id和starts_on在具有相同crp的记录中将始终不同。 id | crp | starts_on | ----------------...

Answer 1

此返回

id  crp starts_on
2   31  2019-06-05
3   20  2018-01-10
5   58  2022-01-01
6   58  2025-02-02

根据我对要求的理解，这似乎是正确的。简而言之

1 - NOT included because its date is in the past ('current' date = 2020-10-02) 
    and its ID is NOT the greatest among records in the past with that CRP.
2 - included because its date is in the past and its ID is the greatest
    among records with that CRP which have dates in the past.
3 - date is in the past, ID is greatest for that CRP with date in the past
4 - NOT included because date is in the future, but CRP is included in recs
    from first subquery.
5 - date is in the future, and CRP does not occur in first subquery
6 - date is in the future, and CRP does not occur in first subquery

db<>fiddle here