Question

I have this query

SELECT distinct username, time
FROM `sadaat`.`wp_loginlog`
where username != 'admin' or username is not null
order by time DESC
limit 0,20

This doesnt give me the distinct records. If I take out time then it does. What can I do to get distinct results there.

if I use

SELECT distinct username
FROM `sadaat`.`wp_loginlog`
where username != 'admin' or username is not null
order by time DESC
limit 0,20

then I can not get the value for time as it will not select the time field

Answer 1

The DISTINCT clause refer to all the attributes in the SELECT clause, not just username.
(actually, it does not make sense to have distinct username and non-distinct time).

For instance if you have row with the same username and different time they will always be displayed

Maybe, if you want some information about time relevant to each single user you can have a look at the group by clause