What is the purpose of Order By 1 in SQL select statement?

Question

I\'m reading through some old code at work, and have noticed that there are several views with an order by 1 clause. What does this accomplish?

Exampl

Answer 1

This is useful when you use set based operators e.g. union

select cola
  from tablea
union
select colb
  from tableb
order by 1;