MYSQL - 查找不同的记录并按另一个字段长度排序

Question

首先，感谢大家花时间帮助解决我的问题。

我有一个由id和content组成的表格

一组示例数据是:

id  content
9   With astonishing insight and poignant precision
8   Whether they find themselves hacking rattles from the tails of snakes or nesting rattles in the hands of their babies.
4   This is a clear-eyed, deeply poignant collection.
12  This book is a dynamic compilation of snapshot tales, each of which encompasses its own sensory-rich world and can be read.
12  This book is an appropriate title for her collection-the prose poems feel revealed.
12  This book is a collection of ekphrastic vignettes set against surreal backdrops fraught with eerie characters faking normalcy.

我需要做的是找到每个唯一id的最短长度content

例如，上面的输出应该是:

id  content
9   With astonishing insight and poignant precision
8   Whether they find themselves hacking rattles from the tails of snakes or nesting rattles in the hands of their babies.
4   This is a clear-eyed, deeply poignant collection.
12  This book is an appropriate title for her collection-the prose poems feel revealed.

到目前为止，我所掌握的明显错误的是:

SELECT DISTINCT id, content FROM t
    GROUP BY id;

感谢您的帮助!

Answer 1

一种方法是计算最短长度，然后将结果连接回来:

select t.id, t.content
from (select id, min(length(content)) as minl
      from t
      group by id
     ) tmin join
     t
     on t.id = tmin.id and length(t.content) = tmin.minl;

注意:如果两个内容长度相同且均为最小值，则返回两者。您的问题没有指定在这种情况下该怎么做。