On Fri, Sep 21, 2012 at 2:23 PM, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: > On Fri, Sep 21, 2012 at 12:39 PM, Benedikt Grundmann > <benedikt.grundmann@xxxxxxxxx> wrote: >> On 21 September 2012 14:04, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: >>> >>> On Fri, Sep 21, 2012 at 4:18 AM, Benedikt Grundmann >>> <benedikt.grundmann@xxxxxxxxx> wrote: >>> > >>> > On 21 September 2012 07:50, Alban Hertroys <haramrae@xxxxxxxxx> wrote: >>> >> >>> >> On 20 Sep 2012, at 20:36, Benedikt Grundmann wrote: >>> >> >>> >> > So named anonymous records / row types seem to be strangely second >>> >> > class. Can somebody clarify the restrictions and rationale or even >>> >> > better >>> >> > show a way to do the equivalent of (made up syntax ahead): >>> >> > >>> >> > select row(1 as a, 2 as b); >>> >> >>> >> select * from (values (1, 2, 3)) a (a, b, c); >>> >> >>> > Thank you very much. This is very interesting. However this again seems >>> > to be strangely limited, because I can neither extract a column from row >>> > that was constructed this way in a scalar position nor expand it: >>> > >>> > proddb_testing=# select (select x from (values (1, 2, 3)) x (a, b, c)); >>> > ?column? >>> > ---------- >>> > (1,2,3) >>> > (1 row) >>> >>> select * from (values (1, 2, 3)) x (a, b, c); >>> select x.* from (values (1, 2, 3)) x (a, b, c); >>> >>> :-) >>> >> I guess I'm not expressing very well what I mean. What you wrote works just >> fine but it only works by introducing a from clause. Where as a row >> expression can be used in scalar position without the need for a from >> clause: >> >> select row(1, 2); > > solutions i use: > *) cast to defined type > postgres=# create type foo as (a int, b int); > postgres=# select (row(1,2)::foo).*; > a | b > ---+--- > 1 | 2 > > *) hstore: > postgres=# select avals(hstore(row(1,2))); > > *) textual manipulation (most fragile) > select * from regexp_split_to_array(row(1,2)::text, ','); > > merlin also, for recent postgres (9.2, or 9.1 with the extension), you can use the row_to_json function and deal with the output that way (either on the client side, or with the up'n'coming pl/v8). merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
