Re: How to define + operator for strings

am 28.04.2006, um 12:59:25 +0300 mailte Andrus folgendes:
> I want to create portable code which runs in other dbms without
> modification.
>
> Unfortunately this other dbms uses + for string concatenation and has no way
> to define operators.
>
> How to define + operator as alias of || operator for strings so I can use
>
> SELECT firstname+ ' '+ lastname

create function _string_plus(text, text) returns text as $$
begin
return $1 || $2;
end;
$$ language plpgsql;

create operator + (
leftarg = text,
rightarg = text,
procedure = _string_plus,
commutator = +
);

test=*# select 'foo' + 'bar';
?column?
----------
foobar
(1 row)

Please read http://www.postgresql.org/docs/8.1/interactive/xoper.html

HTH, Andreas
--
Andreas Kretschmer (Kontakt: siehe Header)
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