From: | "Pavel Stehule" <pavel(dot)stehule(at)gmail(dot)com> |
---|---|
To: | "Peter Eisentraut" <peter_e(at)gmx(dot)net> |
Cc: | Decibel! <decibel(at)decibel(dot)org>, "Pg Hackers" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: array_length() |
Date: | 2008-11-05 13:14:28 |
Message-ID: | 162867790811050514y7dfca722oce4cd44ea5e76a4@mail.gmail.com |
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Lists: | pgsql-hackers |
Hello
2008/11/5 Peter Eisentraut <peter_e(at)gmx(dot)net>:
> Decibel! wrote:
>>
>> ISTM it'd be useful to have an array_length function (since I just wrote
>> one for work ;), so here's a patch. Note that I don't have the docs
>> toolchain setup, so I wasn't able to test the doc patches.
>
> There is a tiny problem with this implementation: It returns null for an
> empty array, not zero. This is because array_lower and/or array_upper
> return null for an empty array, which makes sense for those cases. We could
> fix this by putting a coalesce around the expression, but since the array
> functions return null for all kinds of error cases, this might mask other
> problems. Or we move to a C implementation.
>
we should to write function isempty(anyarray), that returns true when
param is empty.
regards
Pavel Stehule
>
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