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?
What exactly are you trying to accomplish? I can think of a number of ways.
For example, suppose we have a table like:
create table node (
id int primary key,
parent int references node(id),
content text not null
);
We could create a function like this:
CREATE FUNCTION children(node) RETURNS node[] LANGUAGE SQL AS
$$
SELECT array_agg(node) FROM node WHERE parent=$1.id;
$$;
Then we could still do:
select n.children FROM node n WHERE id = 123;
Note that causes two separate scans, but should work.
Best Wishes,
Chris Travers
regards
Sameer
--
Best Wishes,
Chris Travers
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