Derived/calculated column on existing table

Question

I have been going nuts over this issue for some time and I am seeking help.

I have SQL Server table with values, as follows:

Account - Date - Amount - Su         


        

Answer 1

SELECT    l.*, 
          q.summary AS SummaryPreviousYear
FROM      lists l
LEFT JOIN 
     (
          SELECT    Date, 
                    Summary
          FROM      lists 
          WHERE     MONTH(Date) = 12
     ) AS q  
          ON YEAR(l.Date) = YEAR(q.Date) + 1