Re: BUG #5028: CASE returns ELSE value always when type is"char"

Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
>> What I'm most concerned about are the corner cases where strict
>> typing would give one non-error result and the inferred typing
>> results in an error or a different result from the strict typing.
>> I'm willing to argue that those are bugs, at least when the
>> strongly typed behavior is mandated by the SQL standard.
>
> Are there any such cases?  Your interpretation of strict typing
> seems to be that everything is type-labeled to start with, which
> means that type inference doesn't actually have anything to do.

A simple, self-contained example derived from the OP:

test=# create table t (c "char");
CREATE TABLE
test=# insert into t values ('a');
INSERT 0 1
test=# select case when c = 'a' then 'Hey' else c end from t;
 c
---
 H
(1 row)

test=# select case when c = 'a' then 'Hey'::text else c end from t;
  c
-----
 Hey
(1 row)

-Kevin