mysql - 如何在mysql中按升序和降序修改一列

Question

来自以下 Mysql 查询

select (
   case
   when grade < 8 then null 
   else name
   end
   ) as name,
   grade, marks 
from students
join Grades
ON Min_mark = (SELECT MAX(Min_mark) from grades where min_mark <= students.marks)
order by grade desc,name asc

我想根据等级值对订单进行排序，即

生成包含三列的报告:名称、等级和标记。报告必须按年级降序排列——即首先输入较高的年级。如果分配给同一年级 (1-10) 的学生不止一名，则按姓名字母顺序对这些特定学生进行排序。最后，如果成绩低于8，则用“NULL”作为他们的名字，并按照分数从小到大的顺序排列

select (
   case
   when grade < 8 then null 
   else name
   end
   ) as name,
   grade, marks 
from students
join Grades
ON Min_mark = (SELECT MAX(Min_mark) from grades where min_mark <= students.marks)
 case
    when grade <8 then 
        order by grade desc, name asc
    else 
        order by marks asc
 end

但是由于语法错误，第二个查询没有执行。有人可以建议我如何获得所需的结果。提前致谢

Answer 1

我的猜测是这样的:

ORDER BY grade > 10 DESC /* orders by grade>10 records first */
, CASE WHEN grade > 10 THEN grade ELSE null END DESC /* all grade<=10 records will "sort" equally among themselves */
, CASE WHEN grade > 10 THEN name ELSE marks END ASC /* all grade<=10 records will "sort" by `name`, others will sort my `marks`  */