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[问与答] 无开窗函数的情况下可以实现分组后取最大的一条吗?

发表于

MySQL 版本: 5.7

数据如下

id, article_id, comment_id, comment_at
1,  1,           1,         2024-09-13 14:32:39
2,  1,           2,         2024-09-13 14:32:39
3,  1,           3,         2024-09-13 14:32:30
4,  2,           4,         2024-09-13 14:32:30

想要的结果

articel_id,  last_comment_id,  last_comment_at
1,           2,                 2024-09-13 14:32:39
2,           4,                 2024-09-13 14:32:30
  • 试了子查询, id=1,2 的时间一行会导致查询重复, 然后同事给了我一个 SQL (能完成效果)
select article_id, max(concat(comment_at, '_', comment_id )) from xxx group by article_id
  • 除了这样的方式, 还有别的方式吗?

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