Re: There can be only one
От | Andreas Kretschmer |
---|---|
Тема | Re: There can be only one |
Дата | |
Msg-id | 20151011112809.GA6083@tux обсуждение исходный текст |
Ответ на | Re: There can be only one (Andreas Kretschmer <andreas@a-kretschmer.de>) |
Список | pgsql-general |
Andreas Kretschmer <andreas@a-kretschmer.de> wrote: > Create a partial unique index on is_default. as an example: test=# CREATE TABLE payment_via ( id int PRIMARY KEY, provider text NOT NULL, keys hstore NOT NULL DEFAULT '', is_default boolean NOT NULL DEFAULT FALSE ); CREATE TABLE test=*# create unique index idx_default on payment_via(is_default) where is_default; CREATE INDEX test=*# insert into payment_via values (1, 'foo','', true); INSERT 0 1 test=*# insert into payment_via values (2, 'bla','', false); INSERT 0 1 test=*# insert into payment_via values (3, 'blubb','', true); ERROR: duplicate key value violates unique constraint "idx_default" DETAIL: Key (is_default)=(t) already exists. test=*# Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889°
В списке pgsql-general по дате отправления: