Selecting two columns in same table multiple times

Question

I am trying to use the below query that shows country and population of second most and second least populous country. I figured out a way to select the population for those countries but I can't find any good way to implement selection of country names.

Select  Max(population) 
From country Where population < (Select max (population) From country)
Union
Select Min(population)
From country where population > (select Min(population) from country) ;

I found a way for selecting country and population for second most/second least populous country but problem is I can't use union on two selects with 2 ORDER BY (one in each select).

Any idea what I can do to solve my problem? Note: Im using Postgres

Answer 1

select *
from (
    select country, population
    from
        (
            select country, population
            from country
            order by population
            offset 1 limit 1
        ) s

    union

    select country, population
    from
        (
            select country, population
            from country
            order by population desc
            offset 1 limit 1
        ) q
) s