W dniu 02.05.2013 20:45, Tom Lane pisze:
> David Fetter <david@fetter.org> writes:
>> Maybe we can make BEFORE and AFTER implied aliases rather than
>> keywords. What say?
> Well, they still have to be unreserved keywords for their use in
> trigger-related commands, but as far as this feature is concerned
> I think they're best off being handled as automatically-supplied
> aliases. IOW the patch needn't touch gram.y at all.
Well... the syntax which wouldn't conflict with Pl/PgSQL is (draft):
INSERT INTO foo ... RETURNING AFTER.*
UPDATE foo SET ... RETURNING AFTER.*, BEFORE.*
DELETE FROM foo ... RETURNING BEFORE.*
It will not solve the problems:
1. How to access to old rows if the table is named "BEFORE"?
2. Should AFTER for DELETE and BEFORE for INSERT be allowed? If yes what
should they return? I mean: what should be result of:
INSERT INTO foo ... RETURNING BEFORE.*
and
DELETE FROM foo ... RETURNING AFTER.*
?
The best summarize of dropping NEW/OLD keywords for this proposal was
proposed while IRC meeting:
create or replace function ft1(integer) returns integer language plpgsql
as $f$ <<x>> declare r rt1; begin select 1 as a into r; update rt1 r set
a = a + 1 returning XXX into r; raise notice 'r = %', r; return null;
end; $f$;
Regards,
Karol Trzcionka