Constraint Null Value

["Alex Soto" <alex(dot)soto(at)grifols(dot)com>]

I am is Alex, and I m developing a product with PostgreSQL 8.1. I have a 
problem. This problem is that i have some unique constraints with 
multi-columns. The problem is that there is some that of the check 
constraint condition that can be null. As it is described in section 
5.3.3, null of one row is different from the null of other row, so we 
can have two entries with same values inserted because of null value is 
not a considered equal in this comparison.

Is there any administration syntax to change this behavior so null 
values are treated as same value?

Thank you very much.


La información contenida en el presente e-mail es confidencial y está reservada para el uso exclusivo de su destinatario. Se prohíbe estrictamente la distribución, copia o utilización de esta información sin el previo permiso de su destinatario. Si usted no fuera el destinatario, por favor notifíquelo inmediatamente al remitente y elimine el presente mensaje de su sistema informático.

Information contained in this e-mail is confidential and is intended for the use of the addressee only. Any dissemination, distribution, copying or use of this communication without prior permission of the addressee is strictly prohibited. If you are not the intended addressee, please notify the sender immediately by reply and then delete this message from your computer system.