How to use an ALIAS in a PostgreSQL ORDER BY clause?

Question

I have the following query:

SELECT 
    title, 
    (stock_one + stock_two) AS global_stock
FROM
    product
ORDER BY
    global_stock = 0,
    title;
         


        

Answer 1

One solution is to use the position:

select  title, 
        ( stock_one + stock_two ) as global_stock
from product
order by 2, 1

However, the alias should work, but not necessarily the expression. What do you mean by "global_stock = 0"? Do you mean the following:

select  title, 
        ( stock_one + stock_two ) as global_stock
from product
order by (case when global_stock = 0 then 1 else 0 end) desc, title