Question

I have a table like the following:

------------------------------------
Id   FId   UId   Version
1    1     1     1
2    1     2     1
3    1     3     1
4    1     2     2
5    1     3     2
6    1     3     2
7    1     4     2
8    2     1     1
9    2     2     1

then I want the result to be:

--------------------------
FId  UId   Version
1    2     2
1    3     2
1    4     2
2    1     1
2    2     1

How to write the query based on the max ‘Version’ of each FId-UId pair?

Answer 1

The following gives the output requested.

select distinct t2.FId, t2.UId, t2.Version
from
(
    select FId, max(Version) as "Version"
    from MyTable
    group by FId
) t1
inner join MyTable t2 on (t1.FId = t2.FId and t1.Version = t2.Version)
order by t2.FId, t2.UId