MySQL order by first column, sorted by second column

Question

I'm trying to get the correct ORDER BY for my MySQL query, however I can't get the order by correct.

I have two columns:

1. breaking_news = values are NULL or 1
2. news_published_dt = values are DATETIME

How can I sort so that the first output are breaking_news NOT NULL sorted by DATETIME , and then the rest afterwards is just ordered by DATETIME ?

I've tried this, but it gave me no output

ORDER BY CASE WHEN n.breaking_news IS NOT NULL THEN 1 ELSE 2 END, n.news_published_dt DESC

Answer 1

Looks like, you are looking for this:

SELECT 
    * 
FROM 
    tableName 
ORDER BY 
    breaking_news DESC, 
    news_published_dt ASC

Answer 2

SELECT * FROM table_name ORDER BY news_published_dt DESC

Answer 3

select * from 
(select *, 1 Shortby from table 1 where (breaking_news is null)
union all
select *, 2 Shortby from table 1 where (breaking_news=1)
) a
order by Shortby ,news_published_dt Desc

Answer 4

SORT BY in MySQL works differently than what you (me included) would be expected. You cannot do a sort by of two columns and have each of the first sorted by columns sorted according to the second.

DOES NOT WORK:

ORDER BY breaking_news, news_published_dt

RESULT:

breaking_news | news_published_dt
            1 | 2019-04-17
            1 | 2019-04-04
         null | 2019-05-01
         null | 2019-05-06

• Notice that the nulls are sorted correctly, however where breaking_news is 1; the results are not sorted according to what the poster wants.

The only way that I have found to accomplish this; query for the wanted boolean result individually and then union the two together.

THIS DOES WORK:

(SELECT * FROM news_table WHERE breaking_news = 1 ORDER BY news_published_dt)
UNION
(SELECT * FROM news_table WHERE breaking_news <> 1 ORDER BY news_published_dt)

RESULT:

breaking_news | news_published_dt
            1 | 2019-04-04
            1 | 2019-04-17
         null | 2019-05-01
         null | 2019-05-06

For a more thorough explanation of this, check out Edwin Wang's explanation

Answer 5

当 n.break_news 不为 NULL 时使用此顺序，然后 n.break_news ELSE 'zzzzzzzzzzzzzzzzzzzzzzzz' END, n.news_published_dt DESC