MySQL仅选择在列上具有最大值的行

Question

I use the following code to list the jid and count.

Select jid,count(jid) as jidtime 
From Application
Group by jid;

but I also want to show the jid and the max(jidtime),which is jid:4 jidtime:6

I tried, but fail. Need some help...

Select jid, max(jidtime) 
From (Select jid,count(jid) as jidtime From Application
Group by jid) AS T;

Answer 1

You would do this with order by and limit :

Select jid, count(jid) as jidtime 
From Application a
Group by jid
Order by count(jid) desc
Limit 1;

This takes the results, orders them by the second column, and then limits the query to the first row (which should have the highest value).

Answer 2

Use a subquery in an in-clause:

Select * from Application
WHERE jidtime IN (Select Max(jidtime) From Application)

Or just order by descending, and limit, which should be faster:

Select * from Application order by jidtime desc limit 1

Answer 3

i think you have two options. i cant give the excat (tested) code becasue i dont have a mssql right now.

one is something with rank, i dont know the correct code now, but it should be like

 select jid, count(jid) OVER (PARTITION BY jid order by count(jid)) 
 from Application 
 group by jid 

the second option is with a subquery.

select jid, count(jid) as jidtime 
from Application
group by jid
having count(jid) = (select max(count(jid) 
                         from Application 
                         group by jid
                     )