Re: PATCH: psql boolean display

On 20 August 2012 22:10, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> 2012/8/20 Robert Haas <robertmhaas@gmail.com>:
>> On Sun, Aug 19, 2012 at 12:02 PM, Phil Sorber <phil@omniti.com> wrote:
>>> I am providing a patch to allow you to change the output of a boolean
>>> value in psql much like you can do with NULL. A client requested this
>>> feature and we thought it may appeal to someone else in the community.
>>>
>>> The patch includes updated docs and a regression test. The code
>>> changes themselves are pretty simple and straightforward.
>>>
>>> Example from the regression test:
>>>
>>> SELECT true, false;
>>>  bool | bool
>>> ------+------
>>>  t    | f
>>> (1 row)
>>>
>>> \pset booltrue 'foo'
>>> \pset boolfalse 'bar'
>>> SELECT true, false;
>>>  bool | bool
>>> ------+------
>>>  foo  | bar
>>> (1 row)
>>>
>>> \pset booltrue 't'
>>> \pset boolfalse 'f'
>>> SELECT true, false;
>>>  bool | bool
>>> ------+------
>>>  t    | f
>>> (1 row)
>>>
>>> As always, comments welcome.
>>
>> Why not just do it in the SQL?
>>
>> SELECT CASE WHEN whatever THEN 'foo' ELSE 'bar' END AS whatever;
>
> I understand this motivation - although I was more happy with server
> side solution.

Wouldn't a server-side solution risk breaking many things that depends
on such a representation?  You wouldn't be able to pick and choose
what comes out of the server on a per-application basis unless you use
cumbersome CASE clauses in every query that returns boolean data.

It sounds like keeping it at the application level is the least
disruptive, and there is a precedent for such changes, such as NULL
representation.