default constraint using another column in the same table and others

[JamesS]

Is it possible to set the defalt value of a column to the value of another
column in the same table. For example I have tableA with columns B and C.
I want the default value of C to be the value entered in B.

Can I use dataflow constructs(if,else, case) on a check constraint? Using
the aforementioned table, suppose that column B can be null, and I want to
create a check constraint such that B < C, can I create a constraint such
that it is only invoked if both B and C are not null?

The pseudocode:
if b is not null then
impose check constraint(B should be less than C)
otherwise
do nothing

Tnx

[DaveSatz]

No - you need to write a trigger. Defaults can only be constant
expressions, .i.e. system_user or 0
--

HTH,
David Satz
Principal Software Engineer
Hyperion Solutions
{ SQL Server 2000 SP1/7.0 SP3/6.5 SP5a } { Cold Fusion 5/4.5.1 SP2 } { VSS }
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"JamesS" <gipanuhot@yahoo.com> wrote in message
news:3be6cd52$1@147.208.176.211...
>
> Is it possible to set the defalt value of a column to the value of another
> column in the same table. For example I have tableA with columns B and C.
> I want the default value of C to be the value entered in B.
>
> Can I use dataflow constructs(if,else, case) on a check constraint? Using
> the aforementioned table, suppose that column B can be null, and I want to
> create a check constraint such that B < C, can I create a constraint such
> that it is only invoked if both B and C are not null?
>
> The pseudocode:
> if b is not null then
> impose check constraint(B should be less than C)
> otherwise
> do nothing
>
> Tnx