Computed value of a View

I have a view that has 2 columns. The first column is associated with a function for the Units. The second column calculates the Market Value:

View
====
Col1: Unit = get_number_of_units()
Col2: MV = get_number_of_units() * get_unit_value()

I need to call get_number_of_units() twice in the view. Is it possible to changes Col2 to something like: MV = Col1 * get_unit_value()?

Is get_unit_value() being called if I do Select Col1 from View?

Thanks.

No it is not.

Try this:


USE northwind
GO

CREATE function dbo.calc_ok(@val int)
returns int
as
begin
return @val - 2
end

GO

CREATE function dbo.calc_err(@val int)
returns int
as
begin
return 10/@val
end

GO

CREATE VIEW test_calc
as
SELECT EmployeeID
, dbo.calc_ok(EmployeeID) calcok
, dbo.calc_err(dbo.calc_ok(EmployeeID)) calc_err
FROM dbo.Employees

GO

now run this 2 select statements.

This one will include EmployeeID 2 and will result
a division by 0, therefore an error.

Code:

SELECT TOP 2 * FROM test_calc ORDER BY EmployeeID

This one won't.
SELECT TOP 2 EmployeeID FROM test_calc ORDER BY EmployeeID

Bambola.