选择在MySQL Group中获取与max对应的整行

Question

当我使用Max在使用GROUP BY后查找特定MySQL组中字段的最大值时，是否可以获得包含最大值的整行？

Answer 1

我想知道这是否会奏效：

select * from table where id in (select distinct max(id) from table group by name)

Answer 2

I stumbled across this thread when working on some forum code. I wanted to get the latest post for each thread and display it in the list of threads for a particular board.

Quassnoi's answer above was very helpful to me and I was able to adapt it. Here is the code in case it helps anyone else:

SELECT p.id As post_id, p.post_number, p.topic_id
FROM forum_post p, (
    SELECT topic_id, MAX(post_number) As max_post_number
    FROM   forum_post d
    GROUP  BY topic_id) dd
WHERE p.id =
(
    SELECT id
    FROM   forum_post
    WHERE  topic_id = dd.topic_id
    AND    post_number = dd.max_post_number
    ORDER  BY topic_id DESC, post_number DESC, id DESC
    LIMIT  1
)

Answer 3

SELECT  di.id, di.orderer, di.ghigh, di.glow
FROM    (
        SELECT  glow, MIN(orderer) AS orderer
        FROM    t_distinct d
        GROUP BY
                glow
        ) dd
JOIN    t_distinct di
ON      di.id =
        (
        SELECT  id
        FROM    t_distinct ds
        WHERE   ds.glow = dd.glow
                AND ds.orderer = dd.orderer
        ORDER BY
                glow DESC, orderer DESC, id DESC
        LIMIT 1
        )

See this article for more explanations:

• MySQL: Selecting records holding group-wise maximum (resolving ties)

Answer 4

Look at the following query:

SELECT items.*
FROM items, (select @grouping_value:=null) as init
WHERE GREATEST(grouping_field=@grouping_value,
               IF(@grouping_value:=grouping_field,0,0))
ORDER BY grouping_field, sorted_field DESC

The idea is to sort table data by grouping field and sorted field and take the first row from each group