我有三个表。
Page Revision Text
+-----------+-------------+ +-----------+-------------+----------+ +-------------+---------+
| page_id | rev_id | | rev _id | rev_text_id | page_id | | rev_text_id | text |
+-----------+-------------+ +-----------+-------------+----------+ +-------------+---------+
| 1 | 2 | | 1 | 1 | 1 | | 1 | A |
+-------------------------- +------------------------------------+ +-----------------------+
| 2 | 5 | | 2 | 2 | 1 | | 2 | B |
+-------------------------+ +------------------------------------+ +-----------------------+
| 3 | 3 | 2 | | 3 | C |
+------------------------------------+ +-----------------------+
| 4 | 4 | 2 | | 4 | D |
+------------------------------------+ +-----------------------+
| 5 | 4 | 2 |
+------------------------------------+
我想要的输出是:
+--------+-------------+
| rev_id | rev_text_id |
+--------+-------------+
| 1 | 1 |
+----------------------+
| 3 | 3 |
+----------------------+
| 4 | |
+----------------------+
我的目标是找到可以在单个查询中从每个表中删除的 rev_id 和 rev_text_id。由于修订表可以为多个修订保留相等的 rev_text_id,因此我需要排除每个页面的最高 rev_text_id(在第 2 页的示例 4 中)。
我开始涉足以下方面:
SELECT
r.rev_id,r.rev_text_id
FROM revision r, page p, text t
WHERE p.page_id = r.page_id
AND t.rev_text_id = r.rev_text_id
AND p.rev_id != r.rev_id
AND r.rev_text_id not in (
SELECT max(r.rev_text_id)
FROM revision AS r, page AS p
WHERE r.rev_id = p.rev_id
);
但这会跳过我想要的输出中 rev_id 4 的记录,并且不包括“空案例”..
最佳答案
试试这个:
SELECT r.`rev_id`, r.`rev_text_id`
FROM `Revision` AS r
WHERE r.`rev_text_id` NOT IN (SELECT r.`rev_text_id`
FROM `Revision` AS r, `Page` AS p
WHERE r.`rev_id` = p.`page_latest`;)
ORDER BY r.`rev_id`;
这基本上是获取等于 page_latest 的 rev_id,找到与这些 rev_id 关联的 rev_text_id,并使用这些 rev_text_id 作为过滤器。
关于mysql - 选择除最高记录以外的所有记录,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19931601/