MySQL 如何获取与同一列中另一个组的值匹配的组？

Question

Here are the tables:  

  Drinker (name, address)  
  Bar (name, address)  
  Beer (name, brewer)  
  Frequents (drinker, bar, times_a_week)  
  Likes (drinker, beer)  
  Serves (bar, beer, price)

而且，问题是这样的：
找到那些与 Silvie Hume 喜欢同一组啤酒的饮酒者。

我的代码如下：

SELECT *  
FROM drinker d  
JOIN likes l1 ON d.Name = l1.Drinker  
WHERE l1.Beer IN (SELECT Beer FROM likes l2 WHERE l2.Drinker = 'Silvie Hume');

好像我的输出return all drinks that match one of beers Silvie Hume like,我不知道如何select喜欢和Silvie Hume同一套啤酒的饮酒者.有什么帮助吗？谢谢！
我尝试用 = ALL 替换 IN，但它也没有用

Answer 1

一个选项在 Likes table:

上使用自联接

SELECT
    t1.drinker
FROM Likes t1
LEFT JOIN Likes t2
    ON t1.beer = t2.beer AND t2.drinker = 'Silvie Hume'
WHERE
    t1.drinker <> 'Silver Hume'
GROUP BY
    t1.drinker
HAVING
    COUNT(*) = COUNT(t2.beer) AND
    COUNT(*) = (SELECT COUNT(*) FROM Likes WHERE drinker = 'Silvie Hume');

作为解释，HAVING 子句中的第一个条件断言所有给定饮酒者的喜好都与 Silvie Hume 的喜好相匹配。第二个条件涵盖了给定饮酒者的所有喜好都匹配的边缘情况，但 Silvie Hume 也有其他一些喜好。因此，我们断言每个饮酒者的点赞数与 Silvie Hume 相同。

MySQL 如何获取与同一列中另一个组的值匹配的组？

MySQL how to get the group that match the value of another group in the same column?

mysql

join

relational-division