Question

我有一个包含3列的表格：

AuthorID（id可以重复）
JournalName（名称可以重复）
AuthorScore

我需要一个查询，获取JournalName以及所有作者在此期刊中获得最高分数的计数。

提前谢谢。

Answer 1

select 
    maxscorejournalinstances.journalname,
    COUNT(*) as maxscorecount
from
    (
    select 
        journalname
        from
    foo inner join
        (
            select 
                authorid,
                MAX(authorscore) as maxscore
            from
                foo
            group by
                authorid
        ) maxauthorscores
    on foo.AuthorId = maxauthorscores.AuthorId 
    and foo.AuthorScore = maxauthorscores.maxscore
    ) maxscorejournalinstances
group by
    maxscorejournalinstances.JournalName

请注意，如果作者在两个或更多期刊中具有相同的高分，则每个期刊都将包含在结果集中。

Answer 2

SELECT AuthorID, MAX(AuthorScore) as AuthorScore, 
    (
        SELECT JournalName 
        FROM tab t2 
        WHERE t1.AuthorID = t2.AuthorID AND t2.AuthorScore = MAX(t1.AuthorScore)
    ) as JournalName
FROM tab t1
GROUP BY AuthorID

Answer 3

select 
   x.journalname, count(x.authorid)
from tableX x
inner join

(
select authorid, max(authorscore) max_authorscore
from tableX
group by authorid
) tmp on x.authorid=tmp.authorid and x.authorscore=tmp.max_authorscore
group by journalname

Answer 4

这样的事可能有用。

select authorid, journalname, authorscore, max(authorscore) over(parition by authorid)
from <table>
order by journalname

对sql olap函数进行一些研究应该指出正确的方向，如果这不起作用。

Answer 5

听起来你需要2个查询，因为返回的数据无法在一个记录集中返回，数据布局很容易看到。

每个期刊的作者数量，

select JournalName, count(distinct AuthorID) 
from table
group by JournalName

作者每个期刊的最高分，

select JournalName, AuthorID, max(AuthorScore)
from table
group by JournalName, AuthorID

我需要一个检索此结果的查询

5 个答案: