Re: return rows question

Thanks. I had looked into this. But, it's not quite what I was looking
for.

I am writing a set of functions to act as an api to access data in the
database. There are times when I would need to return a set of rows or
even a set of text from a pl/pgsql function based on some logic (no such
thing as logic in SQL).

Any ideas?

Thanks for the help,

L.
On Fri, 14 Jun 2002, Joe Conway wrote:

> Laurette Cisneros wrote:
> > Is there any way to write a function that will return a set of rows? I
> > can't seem to figure it out (in pl/pgsql or some other way)?
> >
> > Thanks,
> >
>
> <This question should probably be moved to the SQL list>
>
> In 7.2.x it is possible to return SETOF sometype using SQL language
> functions and C language functions. However the functionality is pretty
> limited. For example this works:
>
> test=# select * from foo;
> fooid | f2
> -------+-----
> 1 | 11
> 2 | 22
> 1 | 111
> (3 rows)
>
> test=# create or replace function getfoo(int) returns setof int as
> 'select f2 from foo where fooid = $1;' language sql;
> CREATE FUNCTION
> test=# select getfoo(1);
> getfoo
> --------
> 11
> 111
> (2 rows)
>
> But if you want multiple columns:
> test=# drop function getfoo(int);
> DROP FUNCTION
> test=# create or replace function getfoo(int) returns setof foo as
> 'select * from foo where fooid = $1;' language sql;
> CREATE FUNCTION
> test=# select getfoo(1);
> getfoo
> -----------
> 139014152
> 139014152
> (2 rows)
>
> The numbers are actually pointers to the returned composite data type.
> You can do:
>
> test=# select fooid(getfoo(1)), f2(getfoo(1));
> select fooid(getfoo(1)), f2(getfoo(1));
> fooid | f2
> -------+-----
> 1 | 11
> 1 | 111
> (2 rows)
>
> test=# select version();
> select version();
> version
> -------------------------------------------------------------
> PostgreSQL 7.2.1 on i686-pc-linux-gnu, compiled by GCC 2.96
> (1 row)
>
> but it is a bit strange looking. For an example C function which returns
> a set, see contrib/dblink.
>
> In the next release (7.3) things will be substantially better. You will
> be able to do:
>
> test=# select * from getfoo(1);
> fooid | f2
> -------+-----
> 1 | 11
> 1 | 111
> (2 rows)
>
> test=# select version();
> version
> ---------------------------------------------------------------
> PostgreSQL 7.3devel on i686-pc-linux-gnu, compiled by GCC gcc (GCC)
> 3.1 20020205 (Red Hat Linux Rawhide 3.1-0.21)
> (1 row)
>
>
> HTH,
>
> Joe
>
>

--
Laurette Cisneros
The Database Group
(510) 420-3137
NextBus Information Systems, Inc.
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