Обсуждение: Accessing fields in a function that returns a set of composite type - How?

Hello everyone,


I am using tsearch2 to create a search engine for our website. I am
using the tsearch2 guide as my reference and am adapting it to fit our
requirements:

http://www.rhodesmill.org/brandon/projects/tsearch2-guide.html

I have a composite type for search_result. This is the definition:

Composite type "public.search_result"
    Column     |  Type
---------------+---------
 article_id    | integer
 article_title | text
 headline      | text
 rank          | real


I then have a pl/pgsql function that returns a set of "search_result"

CREATE FUNCTION search(text) RETURNS SETOF search_result LANGUAGE sql $$
SELECT article_id, article_title, headline(article_text, q),
rank(article_vector, q)
FROM articles, to_tsquery($1) AS q
WHERE article_vector @@ q ORDER BY rank(article_vector, q) DESC;

To do a full-text search, I only need to do this:

SELECT search('string');

However, running the function gives me a recordset with only one
column ("search"). I'd like to be able to access the fields of the
composite type (search_result) that is returned by the function -
article_id, article_title, headline, and rank. I haven't figured out
how to do this but it's necessary because I want to be able to control
the formatting of the output.

Thanks and best regards,
Matt

--
Stand before it and there is no beginning.
Follow it and there is no end.
Stay with the ancient Tao,
Move with the present.

On 4/19/06, Matt Arnilo S. Baluyos (Mailing Lists)
<matt.baluyos.lists@gmail.com> wrote:
> I have a composite type for search_result. This is the definition:
>
> Composite type "public.search_result"
>     Column     |  Type
> ---------------+---------
>  article_id    | integer
>  article_title | text
>  headline      | text
>  rank          | real
>
>
> I then have a pl/pgsql function that returns a set of "search_result"
>
> CREATE FUNCTION search(text) RETURNS SETOF search_result LANGUAGE sql $$
> SELECT article_id, article_title, headline(article_text, q),
> rank(article_vector, q)
> FROM articles, to_tsquery($1) AS q
> WHERE article_vector @@ q ORDER BY rank(article_vector, q) DESC;
>
> To do a full-text search, I only need to do this:
>
> SELECT search('string');
>
> However, running the function gives me a recordset with only one
> column ("search"). I'd like to be able to access the fields of the
> composite type (search_result) that is returned by the function -
> article_id, article_title, headline, and rank. I haven't figured out
> how to do this but it's necessary because I want to be able to control
> the formatting of the output.

Hmmm... figured it out already. Please disregard my previous post.

You only need to do a...

SELECT * FROM search('search_string');


--
Stand before it and there is no beginning.
Follow it and there is no end.
Stay with the ancient Tao,
Move with the present.

On April 18, 2006 10:37 am, "Matt Arnilo S. Baluyos (Mailing Lists)"
<matt.baluyos.lists@gmail.com> wrote:
> To do a full-text search, I only need to do this:
>
> SELECT search('string');
>
> However, running the function gives me a recordset with only one
> column ("search"). I'd like to be able to access the fields of the
> composite type (search_result) that is returned by the function -
> article_id, article_title, headline, and rank. I haven't figured out
> how to do this but it's necessary because I want to be able to control
> the formatting of the output.
>

In general, a set-returning function looks like a table, ie:

SELECT article_id, article_title, headline, and rank FROM search('string');

Assuming your function works right.  I get an error when trying to call a
set-returning function as SELECT function();, though, so I don't know how
yours is doing anything.

--
Alan