pg.ddx.io pgsql-bugs@postgresql.org mailing list archive
help / color / mirror / Atom feedFunction Error Response Is Not Clear
2+ messages / 2 participants
[nested] [flat]
* Function Error Response Is Not Clear
@ 2025-06-06 02:50 Luke Muther <lmutes8@gmail.com>
2025-06-07 16:05 ` Re: Function Error Response Is Not Clear Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 2+ messages in thread
From: Luke Muther @ 2025-06-06 02:50 UTC (permalink / raw)
To: pgsql-bugs@lists.postgresql.org
To whom it may concern,
Some functions if they are missing the correct arguments give vague error
messages while others give specific ones.
Specific error message example query 1:
SELECT sum();
Specific error message example output 1:
ERROR: function sum() does not exist
LINE 1: SELECT sum();
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.
Specific error message example query 2:
SELECT sum();
Specific error message example output 2:
ERROR: function lower() does not exist
LINE 1: SELECT lower();
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.
Vague error message example query 1:
SELECT nullif();
Vague error message example output 1:
ERROR: syntax error at or near ")"
LINE 1: SELECT nullif();
^
Vague error message example query 2:
SELECT nullif(1);
Vague error message example output 2:
ERROR: syntax error at or near ")"
LINE 1: SELECT nullif(1);
^
Vague error message example query 1:
SELECT coalesce();
Vague error message example output 1:
ERROR: syntax error at or near ")"
LINE 1: SELECT coalesce();
^
These examples it is clear the function is the issue, but in my actual
query there were many parentheses nearby so I thought I had mismatched
parentheses for a while and it sent me hunting for the wrong thing wasting
precious time on a production bugfix mid-crisis. I do not know if any other
function besides NULLIF and COALESCE are affected by this. They are just
the two I happened to test.
Best,
Luke
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: Function Error Response Is Not Clear
2025-06-06 02:50 Function Error Response Is Not Clear Luke Muther <lmutes8@gmail.com>
@ 2025-06-07 16:05 ` Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 0 replies; 2+ messages in thread
From: Tom Lane @ 2025-06-07 16:05 UTC (permalink / raw)
To: Luke Muther <lmutes8@gmail.com>; +Cc: pgsql-bugs@lists.postgresql.org
Luke Muther <lmutes8@gmail.com> writes:
> Some functions if they are missing the correct arguments give vague error
> messages while others give specific ones.
Yeah, it's difficult to move the goalposts here at reasonable cost.
The functions that you are complaining about do not go through the
normal parsing process for functions; instead they have hard-wired
grammar productions:
/*
* Special expressions that are considered to be functions.
*/
func_expr_common_subexpr:
...
| NULLIF '(' a_expr ',' a_expr ')'
...
| COALESCE '(' expr_list ')'
and Bison just doesn't do any better than "syntax error" if it
cannot find a match in the grammar. In these particular cases
we could make the grammar production more agnostic and complain
about wrong-number-of-arguments in parse analysis. However
that idea doesn't go very far, because most of the variants of
func_expr_common_subexpr have weird SQL-spec-mandated special
syntax, eg
| TRIM '(' trim_list ')'
...
trim_list: a_expr FROM expr_list
| FROM expr_list
| expr_list
;
So I don't see an easy way to make more than a very small
dent in the problem. If you're feeling motivated to
research this and look for a better answer, please do.
regards, tom lane
^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2025-06-07 16:05 UTC | newest]
Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2025-06-06 02:50 Function Error Response Is Not Clear Luke Muther <lmutes8@gmail.com>
2025-06-07 16:05 ` Tom Lane <tgl@sss.pgh.pa.us>
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox