这里有一种方法：

select t.*
from t join
     (select letter, rand() as rnd
      from t
      group by letter
     ) tt
     on t.letter = tt.letter
order by tt.rnd;

一种更简单的方法是对字母本身进行计算。这里有一种方法：

select t.*
from t
order by rand(ascii(t.letter));

这是规范的，所以在一行中运行两次会返回相同的结果。

试试这个： For MySQL: ```
SELECT T.Letter
FROM Your_Table T
JOIN (
SELECT *
,RAND()RandumNum
FROM(
SELECT DISTINCT Letter FROM Your_Table
)D
)E ON E.Letter = T.Letter
ORDER BY E.RandumNum

检查一下这把小提琴 `For Sqlite:` ```
CREATE TEMP TABLE tempEmployees AS 
SELECT Letter,RANDOM()RandumNum 
FROM Your_Table
GROUP BY Letter
;

SELECT T.Letter
FROM Your_Table T
JOIN tempEmployees E ON E.Letter = T.Letter
ORDER BY E.RandumNum;

检查一下这把小提琴