Question

I have a table like:

file   MajorVersion MinorVersion
a      0            1
b      0            1
a      0            2
a      0            3
b      1            0
a      1            0
b      1            1

I would like to get each file’s latest version (highest minor version of the highest major version). In this case:

a 1 0
b 1 1

Its seems possible with two joins and group by file, but I thought there maybe a better way. Maybe by use of having?

Answer 1

Only one join required:

SELECT   file, MajorVersion, MAX(MinorVersion) MinorVersion
FROM     my_table NATURAL JOIN (
  SELECT   file, MAX(MajorVersion) MajorVersion
  FROM     my_table
  GROUP BY file
) t
GROUP BY file

See it on sqlfiddle.