How to find sum of multiple columns in a table in SQL Server 2005?

Question

I have a table Emp which has these rows:

Emp_cd | Val1  | Val2  | Val3  | Total
-------+-------+-------+-------+-------
 1     | 1.23  | 2.23  |         


        

Answer 1

Just as a regular SELECT?

SELECT 
   Val1, Val2, Val3,
   Total = Val1 + Val2 + Val3
FROM dbo.Emp

Or do you want to determine that total and update the table with those values?

UPDATE dbo.Emp
SET Total = Val1 + Val2 + Val3

If you want to have this total be current at all times - you should have a computed column in your table:

ALTER TABLE dbo.Emp
ADD CurrentTotal AS Val1 + Val2 + Val3 PERSISTED

Then you will always get the current total - even if the values change:

SELECT 
   Val1, Val2, Val3, CurrentTotal
FROM dbo.Emp