Re: UNIQUE KEY with null value...

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



there are answers why it is that, here is how you can surround the problem
you can create the unique index after you create the table, something like

CREATE TABLE test (
id integer not null primary key,
id_uni integer not null,
cod integer,
name varchar(40));

CREATE UNIQUE INDEX test_id_uni_cod ON test (id_uni, cod) WHERE cod IS NOT NULL;
CREATE UNIQUE INDEX test_id_uni ON test (id_uni) WHERE cod IS NULL;


Diego wrote:
Hi,
I´m a brazilian programmer!

I have a question about Postgres UNIQUE KEY. Look:

(Step 1)
CREATE TABLE test (
id integer not null primary key,
id_uni integer not null,
cod integer,
name varchar(40),
constraint test_uk unique(id_uni, cod)
)

(Step 2)
insert into test (id, id_uni, cod, name)
values (1, 1, null, 'A')

(Step 3)
insert into test (id, id_uni, cod, name)
values (2, 1, null, 'B') =========> [Have the same UNIQUE KEY]

Why postgresql don´t break insertion in this case????

Thanks
Diego Ziquinatti
Brazil



---------------------------(end of broadcast)---------------------------
TIP 4: Have you searched our list archives?

              http://archives.postgresql.org


---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
      subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your
      message can get through to the mailing list cleanly

[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux