Inconsistent format() behavior for argument-count inconsistency
regression=# select format('%s %s', 'foo', 'bar');
format
---------
foo bar
(1 row)
regression=# select format('%s %s', 'foo', 'bar', 'baz');
format
---------
foo bar
(1 row)
regression=# select format('%s %s', 'foo');
ERROR: too few arguments for format
Why do we throw an error for too few arguments, but not too many?
(This came up when I started wondering whether the proposed VARIADIC
feature would really be very useful for format(), since it needs a
format string that matches up with its arguments.)
regards, tom lane
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* Tom Lane (tgl@sss.pgh.pa.us) wrote:
Why do we throw an error for too few arguments, but not too many?
Not sure offhand, though I could see how it might be useful. A use-case
might be that you have a variable template string which is user defined,
where they can choose from the arguments that are passed which ones they
want displayed and how. Otherwise, you'd have to have a bunch of
different call sites to format() depending on which options are
requested.
I'd go look at what C sprintf() does, as I feel like that's what we're
trying to emulate and see what it does.
There is also a patch that I reviewed/commented on about changing format
around a bit. I'm guessing it needs more review/work, just havn't
gotten back around to it yet.
Thanks,
Stephen