Reference an alias elsewhere in the SELECT list

Question

I have the following query:

    select FirstName, LastName,
    Case
     When LastName = \'Jones\'
     then \'N/A\'
    End as Other,
    Case 
      When          


        

Answer 1

You will have to use a SELECT in a SELECT:

SELECT FirstName, LastName, Other, 
    Case When Other is not null 
         then 1 
         else 0 END as Flag
FROM 
(
    select FirstName, LastName,
        Case
         When LastName = 'Jones'
         then 'N/A'
        End as Other
    from yourTable
) x

Or you can reuse the CASE statement for the Other field when evaluating the Flag field:

select FirstName, 
    LastName,
    Case 
        When LastName = 'Jones'
        then 'N/A'
    End as Other,
    case when LastName = 'Jones' -- your Other CASE code here
        then 1
        else 0
    END as flag 
from yourTable