Re: scope quirk in copy in function

Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> writes:
> On 03/23/2015 06:59 AM, Scott Ribe wrote:
>> create or replace function archive_some_stuff() returns void as $$
>> declare cutoff timestamptz;
>> begin
>> cutoff := now() - '1 day'::interval;
>> copy (select * from log where end_when < cutoff) to ...

> "Variable substitution currently works only in SELECT, INSERT, UPDATE,
> and DELETE commands, because the main SQL engine allows query parameters
> only in these commands. To use a non-constant name or value in other
> statement types (generically called utility statements), you must
> construct the utility statement as a string and EXECUTE it."

Yeah. It seems like SELECT-inside-COPY might be worth special casing
though. ISTM this is more or less analogous to the case of PREPARE or
DECLARE CURSOR, which are also utility commands that contain a regular DML
command. I'm pretty sure there is a hack in there that allows parameters
to be transmitted down through PREPARE or D.C. ...

regards, tom lane