How to remove duplicate columns

Question

I have some tables like this Sql Fiddle.

I want this table to select only the following values (remove duplicates):

I use DISTINCT keyword, but this returns the following values:

Please do not ask your questions more than once, especially on the same day, as it risks causing duplicate effort. — halfer, Dec 22 '13 at 17:19

score 3 · Answer 1 · answered Dec 07 '13 at 15:08

3

SELECT distinct greatest(`from`,`to`),least(`from`,`to`)
from `tsk_private_message`

answered Dec 07 '13 at 15:08

Prahalad Gaggar

But then you can't tell what is `from` and what is `to` – juergen d Dec 07 '13 at 15:11
@juergend Thats true!!! – Prahalad Gaggar Dec 07 '13 at 15:11
thank's,very much,:'( – user3077624 Dec 07 '13 at 15:19
And for all column with greatest ,least just(`from`,`to`)??? – user3077624 Dec 07 '13 at 15:25
There is a similar question on StackOverflow covering this which you can adapt: http://stackoverflow.com/questions/18932/how-can-i-remove-duplicate-rows – Liam Dec 07 '13 at 15:30
A very big clue... http://sqlfiddle.com/#!2/a648b/15 – Strawberry Dec 07 '13 at 17:54

1 Answers1