postgresql distinct on one column code example

Example 1: postgresql left join distinct on

Select Distinct On (u.username, u.email)
     u.username
    ,u.email
    ,l.browser
    ,l.login_time
From users u
Join logins l On l.username = u.username
Order By u.username, u.email, login_time Desc
 
                                        ^

Example 2: psql select unique

SELECT
   DISTINCT column1
FROM
   table_name;