Horton

Re: Anonymous code block with parameters

Merlin Moncure <mmoncure@gmail.com>

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From: Merlin Moncure <mmoncure@gmail.com>
To: Hannu Krosing <hannu@2ndquadrant.com>
Cc: Marko Tiikkaja <marko@joh.to>, Vik Fearing <vik.fearing@dalibo.com>, Pavel Stehule <pavel.stehule@gmail.com>, Andres Freund <andres@2ndquadrant.com>, Heikki Linnakangas <hlinnakangas@vmware.com>, Craig Ringer <craig@2ndquadrant.com>, Kalyanov Dmitry <kalyanov.dmitry@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2014-09-19T14:26:17Z
Lists: pgsql-hackers 
On Thu, Sep 18, 2014 at 5:22 PM, Hannu Krosing <hannu@2ndquadrant.com> wrote:
> Though it would be even nicer to have fully in-line type definition
>
> SELECT (tup).* FROM
>   (
>     SELECT CASE WHEN .. THEN ROW(1,2,3)::(a int, b text, c int2)
>             WHEN .. THEN ROW(2,3,4)
>             ELSE ROW (3,4,5) END AS tup
>     FROM ..
>   ) ss

+1.   Workaround at present (which I mostly use during json serialization) is:

SELECT (tup).* FROM
  (
    SELECT CASE WHEN .. THEN
               (SELECT q FROM (SELECT 1, 2, 3) q)
            WHEN .. THEN
               (SELECT q FROM (SELECT 2, 3, 4) q)
            ELSE (SELECT q FROM (SELECT 3, 4, 5) q)
            END AS tup
    FROM ..
  ) ss

If you're talking in line type definitions (which is kinda off topic)
though, it'd be nice to consider:

* nested type definition:
create type foo_t as
(
  a text,
  b int,
  bars bar_t[] as
  (
     c int,
     d text
  ),
  baz baz_t as
  (
    e text,
    f text
  )
);

* ...and recursive type references (not being able to recursively
serialize json is a major headache)
create type foo_t as
(
  path text,
  children foo_t[]
);

merlin