Thanks for every one for help. I got it to work. The reason i used a function is that it calculates the values/attributes from several tables in a pretty complex way. I tried to do this by a view first but couldn't do it. I think it's impossible. The function is always supposed to return only one record with many columns. These columns are used as attributes to the table rows.
I know that I have a lot to learn in postgresql. Perhaps I someday figure out a better way to achieve this. Thanks -Lauri On Wed, Aug 17, 2011 at 5:57 AM, David Johnston <pol...@yahoo.com> wrote: > On Aug 16, 2011, at 14:29, Merlin Moncure <mmonc...@gmail.com> wrote: > >> On Tue, Aug 16, 2011 at 8:33 AM, Harald Fuchs <hari.fu...@gmail.com> wrote: >>> In article >>> <cakwofmjwz3znxcj9radn4ov+krsa-133968yvag3l8m3w3z...@mail.gmail.com>, >>> Lauri Kajan <lauri.ka...@gmail.com> writes: >>> >>>> I have also tried: >>>> select >>>> *, getAttributes(a.id) >>>> from >>>> myTable a >>> >>>> That works almost. I'll get all the fields from myTable, but only a >>>> one field from my function type of attributes. >>>> myTable.id | myTable.name | getAttributes >>>> integer | character | attributes >>>> 123 | "record name" | (10,20) >>> >>>> What is the right way of doing this? >>> >>> If you want the attributes parts in extra columns, use >>> >>> SELECT *, (getAttributes(a.id)).* FROM myTable a >> >> This is not generally a good way to go. If the function is volatile, >> you will generate many more function calls than you were expecting (at >> minimum one per column per row). The best way to do this IMO is the >> CTE method (as david jnoted) or, if and when we get it, 'LATERAL'. >> > > From your statement is it correct to infer that a function defined as > "stable" does not exhibit this effect? More specifically would the function > only be evaluated once for each set of distinct parameters and the resulting > records(s) implicitly cached just like the CTE does explicitly? > > David J. > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
