Question

I have table like this

  id     |     serial_num     |      version     | .....
  1      |         1          |          1       | .....
  2      |         2          |          1       | .....
  3      |         2          |          2       | .....
  4      |         3          |          1       | .....
  5      |         4          |          1       | .....
  6      |         5          |          1       | .....
  7      |         5          |          2       | .....
  8      |         5          |          3       | .....

Now what I want to select is to get rows with max version and unique serialn_num …

The result would be:

  id     |     serial_num     |      version     | .....
  1      |         1          |          1       | .....
  3      |         2          |          2       | .....
  4      |         3          |          1       | .....
  5      |         4          |          1       | .....
  8      |         5          |          3       | .....

My SQL is a bit more complicated and that is why I don’t solve the problem by using MAX()… I have few left joins etc …

any ideas?

Best regards and thank you for your time!

Answer 1

Try this:

SELECT yourtable.*
FROM yourtable
WHERE (serial_num, version) in (select serial_num, max(version)
                                from yourtable
                                group by serial_num)

Subquery will return the maximum version for serial_num, so this will return all rows where serial_num has the maximum value. See this fiddle.