Inheritance is completely broken [was: Re: Creating foreign key constraint to child table?]

Dimitri pointed out (the post does not seem to have appered yet) that you can also do:

    test=# create table foo(id integer primary key);    NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index
'foo_pkey'for table 'foo'    CREATE    test=# create table bar () inherits (foo);    CREATE    test=# insert into foo
values(1);    INSERT 12734236 1    test=# insert into foo values (1);    ERROR:  Cannot insert a duplicate key into
uniqueindex foo_pkey    test=# insert into bar values (1);    INSERT 12734238 1    test=# select * from foo;     id
----     1      1    (2 rows)
 

So inheritance does seem to be completely broken.  There is also an entry in the TODO list

    Allow inherited tables to inherit index, UNIQUE constraint, and primary key, foreign key [inheritance]

which seems to be related.  It doesn't have a dash, so I guess I won't hold my breath....


Now I'm sad.


Allan.


Allan Engelhardt wrote:

> Stephan Szabo wrote:
>
> > On Sun, 5 Aug 2001, Allan Engelhardt wrote:
>
> [see new example below]
>
> > Not that this is related to what you asked about precisely (I saw the
> > response you made), but the query above also doesn't do what you think
> > it does right now.  It currently makes a reference to only foo, not
> > any subchildren of foo.
>
> Oh, man!  You are right, but this sux big time: there should not be an asymmetry between a FOREIGN KEY constraint and
theSELECT statement.  Now that the default is SQL_INHERITANCE ON, it should be the default for the constraint as well,
IMHO.
>
> 1. Am I the only one who thinks this is a bug?
>
> 2. How would I get the behaviour I expect?  Write my own trigger? :-P
>
>     --- Allan.
>
> test=# create table foo (id integer primary key);
> test=# create table bar () inherits (foo);
> test=# create table baz (bar integer,
>        constraint fk_bar foreign key (bar) references foo(id));
> test=# insert into foo values (1);
> test=# insert into bar values (2);
> test=# insert into baz values (2);
> ERROR:  fk_bar referential integrity violation - key referenced from baz not found in foo
> test=# select * from foo where id = 2;
>  id
> ----
>   2
> (1 row)
>
> test=#