From: | Andreas <maps(dot)on(at)gmx(dot)net> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | what about uniqueness of inherited primary keys |
Date: | 2003-12-28 20:17:27 |
Message-ID: | 3FEF3A57.4080407@gmx.net |
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Thread: | |
Lists: | pgsql-general |
Hello list,
what about uniqueness of inherited primary keys ?
eg you have :
create table objects (
id int4,
date_created timestamp(0),
primary key (id)
);
create table persons (
firstname varchar(100),
lastname varchar(100)
) inherits (objects);
now ...
insert into objects (id) values (1);
A repetition of this line would cause an unique-constraint error of
objects_pkey.
insert into persons (id, firstname, lastname) values (1, 'Super', 'Man');
insert into persons (id, firstname, lastname) values (1, 'Bat', 'Man');
works though it violates the inherited constraint.
A select * from objects; shows id=1 three times.
delete * from objects; empties both tables.
after ALTER TABLE public.persons ADD CONSTRAINT persons_pkey PRIMARY
KEY(id);
I can still insert at least one record with id=1 in each table.
select count(*) from objects where id=1;
results 2
Shouldn't we expect to have unique entries in a primary key collumn ?
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