Re: Support UPDATE table SET(*)=...

On Fri, Oct 17, 2014 at 10:16 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Marko Tiikkaja <marko@joh.to> writes:
>> local:marko=#* create table foo(f int);
>> CREATE TABLE
>> local:marko=#* update foo f set f=1;
>> UPDATE 0
>
>> This query would change meaning with your suggestion.
>
> I think it wouldn't; Merlin is proposing that f would be taken as the
> field name.  A more realistic objection goes like this:
>
> create table foo(f int, g int);
> update foo x set x = (1,2);  -- works
> alter table foo add column x int;
> update foo x set x = (1,2,3);  -- no longer works
>
> It's not a real good thing if a column addition or renaming can
> so fundamentally change the nature of a query.

That's exactly how SELECT works.  I also dispute that the user should
be surprised in such cases.

merlin