为什么我似乎不能同时按 2 列排序？

Question

我目前在这里遇到了这个问题。我正在尝试按 DESC 顺序订购 2 列，但一次似乎只有一列有效。我需要在 DESC 中订购 Main_Actor_Payment 和 Supporting_Actor_Payment，但它似乎不起作用。请有人帮我解决这个问题。

SELECT main_actor.First_Name,
        main_actor.Last_Name,
        main_actor.Payment_amount AS MAIN_ACTOR_PAYMENT,
        supporting_actors.First_Name,
        supporting_actors.Last_Name,
        supporting_actors.Payment_amount AS SUPPORTING_ACTOR_PAYMENT
FROM main_actor
INNER JOIN supporting_actors USING(MOVIE_ID)
ORDER BY supporting_actors.Payment_amount DESC, main_actor.Payment_amount DESC;

Current output of query

Answer 1

如果我很好地理解你的问题，你需要合并 supporting_actors 和 main_actors 表以获得特定的 movie_id，然后根据 payment_ammount 对它们进行降序排序（主要演员和配角）。如果这是你的意思，你可以使用这个查询：

SELECT * FROM (
        SELECT main_actor.First_Name,
               main_actor.Last_Name,
               main_actor.Payment_amount AS `Payment_Ammount`,
               "main_actor" as `Actor_Type`,
               MOVIE_ID
        FROM 
        main_actor
        union all
        SELECT
               supporting_actors.First_Name,
               supporting_actors.Last_Name,
               supporting_actors.Payment_amount AS `Payment_Ammount`,
               "supporting_actor" as `Actor_Type`,
               MOVIE_ID
        FROM 
        supporting_actors) a
WHERE a.MOVIE_ID = "La La Land"
ORDER BY a.`Payment_Ammount` DESC;

为什么我似乎不能同时按 2 列排序？

Why I can't seem to order by 2 columns at the same time?

mysql

sql

sql-order-by