I would like to use the value calculated in one column in another colum by using it's alias. However, when I try that, I get an 'Invalid Column Name' error.

for example,

SELECT
sum(Price) as 'Sum_Price',
('Sum_Price' / 3) as 'One_Third_Sum_Price'

The SELECT clause can only refer to columns from tables in the FROM clause, so that won't work. Of course, you can do this:

SELECT
sum(Price) as 'Sum_Price',
sum(Price) / 3 as 'One_Third_Sum_Price'

Or you can do this:

SELECT
Sum_Price
Sum_Price / 3 as One_Third_Sum_Price
FROM
( SELECT sum(Price) as 'Sum_Price'
FROM ...
)