MySQL：按最新的日期时间列排序？

Question

这是我添加排序前的查询：

SELECT `picture` 
FROM `profile_data` 
WHERE `profile_id` IN (
    SELECT `profile_id` FROM `collection_entries` WHERE `collection_id` = 2
) 
LIMIT 10;

我试过这样添加顺序：

SELECT `picture` 
FROM `profile_data` 
WHERE `profile_id` IN (
    SELECT `profile_id` 
    FROM `collection_entries` 
    WHERE `collection_id` = 2 
    ORDER BY `created_at` DESC
) 
LIMIT 10;

虽然我收到了这个问题：

This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'

有没有办法做我想做的事？

Answer 1

您可以加入，因此 created_at 列在外部查询中可用于排序：

SELECT `picture` 
FROM `profile_data` pd
INNER JOIN `collection_entries` ce ON ce.`profile_id` = pd.`profile_id`
WHERE ce.`collection_id` = 2
ORDER BY ce.`created_at` DESC
LIMIT 10;

这假设每个 profile_data 在 collection_entries 中不超过一行。如果不是这种情况，那么您需要先 pre-aggregate。所以：

SELECT `picture` 
FROM `profile_data` pd
INNER JOIN (
    SELECT `profile_id`, MAX(`created_at`) `created_at`
    FROM `collection_entries` 
    WHERE `collection_id` = 2
    GROUP BY `profile_id`
) ce ON ce.`profile_id` = pd.`profile_id`
ORDER BY ce.`created_at` DESC
LIMIT 10;

MySQL：按最新的日期时间列排序？

MySQL: Order by newest datetime column?

mysql

sql

inner-join

subquery

sql-order-by