Question

I have a query with a where cluse like that:

WHERE (scalar-subquery1) > (scalar-subquery2)

And it works fine. There can be any operator here instead of “greater than” (“>”) between queries.

Now I want to give a names for these queries so that I can reference them in select clause, so I tried:

SELECT q1,q2 ... WHERE (scalar-subquery1) as q1 > (scalar-subquery2) as q2

But there is syntax error reported between as q1 and > operator. Any way to work around this problem?

Answer 1

You can do this as a subquery:

select q1, q2
from (select (scalar-subquery1) as q1, (scalar-subquery2) as q2
     ) t
where q1 < q2 

Or as a cross join:

select q1.val, q2.val
from(scalar-subquery1) as q1 cross join
    (scalar-subquery2) q2
where q1.val < q2.val

The third option is a variant of the first:

select t.*
from (select <current select>
             (scalar-subquery1) as q1, (scalar-subquery2) as q2
      from <current from>
     ) t
where q1 < q2