Re: BUG #14363: CASE against a literal value produces correct against, same expression against a column null doesn't

On Mon, Oct 10, 2016 at 11:56 AM, <hcate3@gmail.com> wrote:

> The following bug has been logged on the website:
>
> Bug reference:      14363
> Logged by:          Henry Cate
> Email address:      hcate3@gmail.com
> PostgreSQL version: 9.5.2
> Operating system:   x86_64-pc-linux-gnu
> Description:
>
>
> ybd_test=3D# select version();
>                                                       version
>
> ------------------------------------------------------------
> --------------------------------------------------------
>  PostgreSQL 9.5.2 on x86_64-pc-linux-gnu, compiled by clang version
> 3.8.0-2ubuntu3 (tags/RELEASE_380/final), 64-bit
>

=E2=80=8BSame result in 9.3.12

=E2=80=8BIt seems like "case" is too complex an expression to be embedded i=
nto the
<..."simple" form of CASE expression...>

SELECT
case (
    case decimal_9_1
      when decimal_18_1 then 0
      when decimal_9_1  then 1
   end
)
    when 1 then 2
    when 0 then 3
  end

https://www.postgresql.org/docs/9.5/static/functions-conditional.html

I suspect this is some kind of long-standing bug that hasn't been seen due
to this being a unusual way to write a case expression - mainly since the
embedded case evaluates correctly if it is done as a top-level expression.

David J.