On Wed, Aug 7, 2013 at 4:57 AM, Sameer Thakur <samthakur74@gmail.com> wrote:
> I wanted to create a composite datatype to represent a Node. So it would
> have a few attributes and an array of type Node which is the children of
> this node.
> create type Node as (r integer, s integer, children Node []);
> But i get error type Node[] does not exist. I understand that Node is not
> defined hence the error.
> But how do i get around this problem?
I just wonder how are you going to use this kind of types?
In 9.3 you will be able to use foreign keys with arrays like it is describe here
http://blog.2ndquadrant.com/postgresql-9-3-development-array-element-foreign-keys/
eg.
create table node as (
id integer primary key,
r integer, s integer,
children integer[] element references node
);
so you could download 9.3rc2 and experimant with it.
Now (on <=9.2.x) you can create the table without FK
create table node as (
id integer primary key,
r integer, s integer,
children integer[]
);
and check integrity by triggers.
--
Kind regards,
Sergey Konoplev
PostgreSQL Consultant and DBA
http://www.linkedin.com/in/grayhemp
+1 (415) 867-9984, +7 (901) 903-0499, +7 (988) 888-1979
gray.ru@gmail.com
