SQL - 指定的字母顺序

Question

我想要 Completion_Status 列的特定顺序，如下所示:

已完成、通过、未完成和失败

我该如何订购？我想定义上面的顺序。

我试过 CASE 但它给了我一个错误，如期待 NUM 不是 CHAR。

select DISTINCT
  u.first_name || ' ' ||  u.last_name  "Employee_Name",
  rco.title "Course_Name",
  decode(p.status,'P','Passed', 'F','Failed', 'C','Completed', 'I','Incomplete', 'Not Attempted') "Completion_Status",

   to_char(p.completed_date,'YYYY-MM-DD') "Date_Completed"
   from
   offering o, offering_enrollment oe, users u ,  performance p, offering_content_object c, content_object rco
  where
  o.id = oe.offering_id  and
  u.id = oe.user_id and
  o.content_object_id = c.id AND
  p.content_object_id = c.source_id and
  p.content_object_id = rco.id AND
  p.user_id(+) = u.id  and
  u.id in ( select id
                  from users
                  where manager_id = $user.id$) 
                  AND
p.content_object_id NOT IN (41453457, 130020319, 43363877)
order by 
"Employee_Name", "Completion_Status"

Answer 1

您可能可以使用以下内容:

ORDER BY "Employee_Name", CASE "Completed_Status"
                          WHEN 'Completed'  THEN 0
                          WHEN 'Passed'     THEN 1
                          WHEN 'Incomplete' THEN 2
                          WHEN 'Failed'     THEN 3
                          ELSE                   4
                          END;

您可能需要更改 CASE 以处理原始“p.status”值，在这种情况下，WHEN 条件也会发生变化:

ORDER BY "Employee_Name", CASE p.status
                          WHEN 'C' THEN 0
                          WHEN 'P' THEN 1
                          WHEN 'I' THEN 2
                          WHEN 'F' THEN 3
                          ELSE          4
                          END;