"David E. Wheeler" <david@justatheory.com> writes:
> I’ve been happily using the array-to-element concatenation operator || to append a single value to an array, e.g,
> SELECT array || 'foo';
> And it works great, including in PL/pgSQL functions, except in an
> exception block.
Hm, really?
regression=# create table zit (things text[]);
CREATE TABLE
regression=# insert into zit values(array['foo','bar']);
INSERT 0 1
regression=# select things || 'baz' from zit;
ERROR: malformed array literal: "baz"
LINE 1: select things || 'baz' from zit; ^
DETAIL: Array value must start with "{" or dimension information.
I think the problem here is that without any other info about the
type of the right-hand argument of the || operator, the parser will
assume that it's the same type as the left-hand argument; which
is not unreasonable, because there is an array || array operator.
If you are more specific about the type of the RHS then it's fine:
regression=# select things || 'baz'::text from zit; ?column?
---------------{foo,bar,baz}
(1 row)
> Note that it’s fine with the use of || outside the exception block, but
> not inside!
Don't see why an exception block would have anything to do with it.
regards, tom lane
