Oracle order by descending with NULL last

Question

my objective is, to print the result of the query in "DESCENDING" order. but the problem is, the rows with NULL values went on top of the list.. how to put the null rows at the bottom, if the order by is descending?

select mysubcat.subcat
       , mysubcat.subcatid as subcat_id
       , (select SUM(myad.PAGEVIEW) 
           from myad 
            where MYAD.CREATEDDATE between  '01-JUL-13 02.00.49.000000000 PM' and '13-JUL-13 02.00.49.000000000 PM'
            AND MYAD.status = 1 
            and  MYAD.mobileapp IS NULL
            and myad.subcatid = mysubcat.subcatid )as web_views 
from mysubcat 
order by web_views desc;

the sample result goes like this

                             SUBCAT_ID    WEB_VIEWS
Swimming Lessons                56        (null)    
Medical Services                17        (null)
Mobile Phones & Tablets         39        6519
Home Furnishing & Renovation   109        4519

the order is in the descending order, I just want to put the rows with null values at the bottom of the printed result, so how?

Answer 1

You can use DESC NULLS LAST to achieve that.

Here is the official documentation from Oracle.

NULLS LAST

Specifies that NULL values should be returned after non-NULL values.

Answer 2

Use a case

order by case when web_views is not null 
              then 1 
              else 2 
         end asc, 
         web_views desc;