Use value of a column for another column (SQL Server)?

Question

lets say I have a huge select on a certain table. One value for a column is calculated with complex logc and its called ColumnA. Now, for another column, I need the val

Answer 1

You could solve this with a subquery and column aliases.

Here's an example:

SELECT MaxId + 10
FROM (SELECT Max(t.Id) As MaxId
      FROM SomeTable t) As SomeTableMaxId