Обсуждение: Change in behavior of string concat operator

Benjamin Krajmalnik написа:
> I just migrated from 8.1 to 8.3, running on FreeBSD 7.0 amd64.
> Running 8.3.5
[...]
> Select userid::varchar || accountno::varchar || requestdate::date as
> newcolumn from table
> At the very least, the documentation should be updated to reflect the
> new behavior, although I believe this is a bug.


http://www.postgresql.org/docs/current/static/release-8-3.html#AEN86272



--
Milen A. Radev

Thanks.

Then we have an inconsistency between this and the documentation for the || operator, where it is showing the abilty to
concatnumeric types without explicit casting. 

http://www.postgresql.org/docs/8.3/static/functions-string.html


> -----Original Message-----
> From: pgsql-admin-owner@postgresql.org
> [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Milen A. Radev
> Sent: Saturday, December 06, 2008 12:49 PM
> To: pgsql-admin@postgresql.org
> Subject: Re: [ADMIN] Change in behavior of string concat operator
>
> Benjamin Krajmalnik написа:
> > I just migrated from 8.1 to 8.3, running on FreeBSD 7.0 amd64.
> > Running 8.3.5
> [...]
> > Select userid::varchar || accountno::varchar ||
> requestdate::date as
> > newcolumn from table At the very least, the documentation should be
> > updated to reflect the new behavior, although I believe
> this is a bug.
>
>
> http://www.postgresql.org/docs/current/static/release-8-3.html
> #AEN86272
>
>
>
> --
> Milen A. Radev
>
>
> --
> Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
> To make changes to your subscription:
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>

Benjamin Krajmalnik написа:
> Thanks.
>
> Then we have an inconsistency between this and the documentation for the || operator, where it is showing the abilty
toconcat numeric types without explicit casting. 
>
> http://www.postgresql.org/docs/8.3/static/functions-string.html

On second reading of your post (and the documentation) we are both wrong
- the _string_ concatenation operator works when at least one of the
operands is a string.

>
>> -----Original Message-----
>> From: pgsql-admin-owner@postgresql.org
>> [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Milen A. Radev
>> Sent: Saturday, December 06, 2008 12:49 PM
>> To: pgsql-admin@postgresql.org
>> Subject: Re: [ADMIN] Change in behavior of string concat operator
>>
>> Benjamin Krajmalnik написа:
>>> I just migrated from 8.1 to 8.3, running on FreeBSD 7.0 amd64.
>>> Running 8.3.5
>> [...]
>>> Select userid::varchar || accountno::varchar ||
>> requestdate::date as
>>> newcolumn from table At the very least, the documentation should be
>>> updated to reflect the new behavior, although I believe
>> this is a bug.
>>
>>
>> http://www.postgresql.org/docs/current/static/release-8-3.html
>> #AEN86272
[...]


--
Milen A. Radev

On Mon, 8 Dec 2008, Benjamin Krajmalnik wrote:

> Thanks.
>
> Then we have an inconsistency between this and the documentation for the
> || operator, where it is showing the abilty to concat numeric types
> without explicit casting.
>
> http://www.postgresql.org/docs/8.3/static/functions-string.html

What that page appears to say in the note and table is that you can
concatenate a string and a non-string like varchar and integer, not
multiple non-strings like numeric and integer. What specifically were you
looking at on the page?

Thanks, Stephan and Milen.
Everything is clear now.
I had a change in the behavior moving from 8.1 to 8.3, and the automatic
typecasting prior to 8.3 blurred the intended behavior as per the
documentation.