Fw: Re: GROUP_CONCAT in PostgreSQL

----- Original Message -----
From: "Barry Lind" <blind(at)xythos(dot)com>
To: <m(dot)popp(at)db4free(dot)net>
Sent: Thursday, January 05, 2006 8:37 PM
Subject: RE: Re: GROUP_CONCAT in PostgreSQL

Markus,

Please send this to the postgres jdbc mailing list.

--Barry

-----Original Message-----
From: m(dot)popp(at)db4free(dot)net [mailto:m(dot)popp(at)db4free(dot)net]
Sent: Thursday, January 05, 2006 12:37 AM
To: Barry Lind
Cc: chriskl(at)familyhealth(dot)com(dot)au
Subject: Fw: Re: GROUP_CONCAT in PostgreSQL

Hi Barry,

looks like I've found a bug in the PostgreSQL JDBC driver
(postgresql-8.0-314.jdbc3.jar and postgresql-8.1-404.jdbc3.jar).

I have installed the MySQL compatibility functions
(http://pgfoundry.org/projects/mysqlcompat/) in a schema named mysql.
Running the query (which you find below in my mail to Christopher
Kings-Lynne and in the attached source file) works fine with psql and
other client tools, but from a java application, I get the error
message "org.postgresql.util.PSQLException: Eingabe/Ausgabe-Fehler {0}
beim Senden an das Backend.".

I have attached the source file where the error occurs, on line 92,
maybe it helps you for debugging ;-).

Thank you!

Regards,
Markus Popp

Am 05.01.2006 um 02:34 Uhr schrieb Christopher Kings-Lynne:
> Hi Markus,
>
> I guess it must be some bug in the PostgreSQL JDBC driver or something
:(
>
> Ask them perhaps: http://jdbc.postgresql.org/
>
> Chris
>
>
> Markus Popp wrote:
> > Hi,
> >
> > thank you very much - that's great. I think it's good if there's an
amicable
> > relationship between PostgreSQL and MySQL and their Communities :-).
> >
> > There's a little problem that I have, not with the group_concat
function, as
> > it works perfectly well from psql and other client tools, but if I
run this
> > query in a Java program:
> >
> > SELECT a.constraint_name, a.table_name, a.constraint_type,
> > mysql.group_concat(b.column_name), c.table_name, c.column_name
> > FROM information_schema.table_constraints a INNER JOIN
> > information_schema.key_column_usage b
> > ON a.constraint_name = b.constraint_name LEFT JOIN
> > information_schema.constraint_column_usage c
> > ON a.constraint_name = c.constraint_name AND a.constraint_type =
'FOREIGN
> > KEY'
> > GROUP BY a.constraint_name, a.table_name, a.constraint_type,
c.table_name,
> > c.column_name
> > ORDER BY a.constraint_name, a.table_name
> >
> > ... I get the Exception:
> >
> > "org.postgresql.util.PSQLException: Eingabe/Ausgabe-Fehler {0} beim
Senden
> > an das Backend."
> >
> > which means something like "Input/Output-Error {0} sending (what?)
to the
> > backend".
> >
> > The connection seems to be OK, but this query fails (only in Java)
for some
> > reason that I can't find out why.
> >
> > Do you have an idea? Thank you!
> >
> > Cheers,
> > Markus