Ruben Blanco wrote on 08.03.2011 00:30:
Hi: Is there anyway to create a unique index or constraint on part of a column? Something like this, but something that works ;-) ALTER TABLE invoices ADD CONSTRAINT cons UNIQUE (EXTRACT(YEAR FROM invoice_date), innvoice_number); Thanks for any help. Ruben,
CREATE UNIQUE INDEX idx_cons ON invoices (EXTRACT(YEAR FROM invoice_date), innvoice_number); The only difference to a unique constraint is, that it cannot be used as the target of a foreign key constraint. Regards Thomas -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
