我有一个消息表，我想从中获取“user1”的最新联系人，现在该表如下所示：我能得到的最接近的sql查询是
SELECT receiver, sender, time from message where receiver = 'user1' OR sender = 'user1' group by receiver, sender ORDER by time desc
它回来了但它应该返回只包含不同的“user2”、“host1”的结果，但该行重复了两次
f4t66c6m1#
正如@akina所建议的，通过此查询获得的预期结果：
SELECT CASE WHEN receiver = 'user1' THEN sender ELSE receiver END AS contact, max(time) AS time FROM message WHERE receiver = 'user1' OR sender = 'user1' GROUP BY CASE WHEN receiver = 'user1' THEN sender ELSE receiver END
它回来了
1条答案
按热度按时间f4t66c6m1#
正如@akina所建议的，通过此查询获得的预期结果：
它回来了
