mysql操作中 出现You can‘t specify target table for update in FROM clause错误的解决方法

UPDATE StuCose
SET Grade=60
WHERE Sno IN(
          SELECT Sno
      FROM stucose 
       WHERE Grade<=ALL(
          SELECT MIN(Grade)
          FROM stucose s2
          WHERE  s2.Cno IN(
        SELECT Cno
        FROM cose
        WHERE Cname='DS'
          ) 
      )
)  
;

UPDATE StuCose
SET Grade=60
WHERE Sno IN(
   SELECT Sno
   FROM (
     SELECT Sno
      FROM stucose 
       WHERE Grade<=ALL(
          SELECT MIN(Grade)
          FROM stucose s2
          WHERE  s2.Cno IN(
        SELECT Cno
        FROM cose
        WHERE Cname='DS'
          ) 
      )) AS a
)  
;