Date parsed: 20/10/2007 17:41:20
Date: Sat, 20 Oct 2007 17:41:20 GMT
user defined functions must be deterministic - give the same output for the
same input. I think one reason this restriction is there is so that sql can
eliminate performing second and third calls to your function. That said, I
don't know if it will call it more than once. You can insure it won't by
using a derived table.
select t.id, value, dbo.calc1(value) as val1, dbo.calc2(value) as val2
from
(
select id, calcvalue(id) as value
from tabletest
) as t
Jeremy wrote:
>I've got 3 functions. one that calculates a value, and two other ones that
>return a value based on the value returned by the first.
>
>I use these in a view
>example:
>
>select
> dbo.calcvalue(t.[id]) as value,
> dbo.calc1(calcvalue(t.[id]) )) as val1,
> dbo.calc2(calcvalue(t.[id]) )) as val2
>from
> tabletest t
>
>will calcvalue() get called 3 times? or would it be more efficient to use
>two views.
>
>example:
>
>view 1:
>select
> dbo.calcvalue(t.[id]) as value
>from
> tabletest t
>
>view 2:
>select
> dbo.calc1(value) as val1,
> dbo.calc2(value) as val2
>from
> view1
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