PostgreSQL 7.4.1 and pgdb.py

[Manuel Tejada]

Hi
My box: RedHat 9.0, Pentium III

Recently I upgraded from PostgreSQL 7.3.2 to PostgreSQL 7.4.1.
The PostgreSQL 7.3.2's rpms were installed from RehHat CDs
The PostgreSQL 7.4.1's rpms I used to upgrade were downloaded from RHEL3
subdirectory (of the mirror
ftp://ftp4.ar.postgresql.org/pub/mir.../redhat/rhel3).

The upgrade is working well, even I can connect to PostgreSQL from a PHP
script.

Before upgrading I used to connect to PostgresQL using pgdb.py (part of
PyGreSQL that comes with one of the rpms I guess). The sintaxis I was using
from interactive shell were:

---------------

import pgdb
dbConnect = pgdb.connect(ds n='localhost:or acle', user='manuel', password='')cursor = dbConnect.curso r()
cursor.execu te("select * from address")
while (1): .... row = cursor.fetchone ()
.... if row == None:
.... break
.... print row
....
['BAILEY','WILLI AM',None,None,N one,None,'213-293-0223',None]
['ADAMS','JACK', None,None,None, None,'415-453-7330',None]
-
-cursor.close ()
dbConnect.cl ose() -----------------------

As you can see, the connection and fechting were successful.

But now when I input the same sintaxis with the new Installation(Po stgreSQL
7.4.1), I get an error when I enter rhe four line:

----------------import pgdb
dbConnect = pgdb.connect(ds n='localhost:or acle', user='manuel', password='')cursor = dbConnect.curso r()
cursor.execu te("select * from address")

Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/usr/lib/python2.2/site-packages/pgdb.py", line 189, in execute
self.executeman y(operation, (params,))
File "/usr/lib/python2.2/site-packages/pgdb.py", line 221, in executemany
desc = type[1:2]+self ._cache.getdesc r(typ[2])
File "/usr/lib/python2.2/site-packages/pgdb.py", line 149, in getdescr
self ._source.execut e(
_pg.error: ERROR: non exist the column "typprtlen"
------------------

By the way the types of columns from address table are:
lastname varchar(25)
firstname varchar(25)
street varchar(30)
city varchar(15)
state varchar(2)
zip int
phone varchar(12)
ext varchar(5)

My questions:

-Anybody knows why I can't connect to PostgreSQL using the pgdb.py module
now?
- Perhaps the sintaxis has changed?
Manuel Tejada
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[Jeff Davis]

> >>>cursor.execu te("select * from address")

Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/usr/lib/python2.2/site-packages/pgdb.py", line 189, in execute
self.executeman y(operation, (params,))
File "/usr/lib/python2.2/site-packages/pgdb.py", line 221, in executemany
desc = type[1:2]+self ._cache.getdesc r(typ[2])
File "/usr/lib/python2.2/site-packages/pgdb.py", line 149, in getdescr
self ._source.execut e(
_pg.error: ERROR: non exist the column "typprtlen"

That's a column in a system catalog table (starts with "pg_"). The
pgdb.py must be trying to access an out of date version of the system
catalog.

You can probably get an updated pgdb.py somehow, or you can just use
"import pg" which has a different interface (non DBAPI-2.0 compliant)
but should work fine (since it doesn't try to access system catalogs,
it's more of a low-level PG interface for python).

In short, the problem exists in pgdb.py, which is trying to access
information in an out-of-date way.

Regards,
Jeff Davis


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[Alvaro Herrera]

On Fri, Jan 30, 2004 at 07:42:27PM -0800, Jeff Davis wrote:

You can probably get an updated pgdb.py somehow, or you can just use
"import pg" which has a different interface (non DBAPI-2.0 compliant)
but should work fine (since it doesn't try to access system catalogs,
it's more of a low-level PG interface for python).

Keep in mind that there's also psycopg and PyGreSql, as far as Python
interfaces go.

--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Pido que me den el Nobel por razones humanitarias" (Nicanor Parra)

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[Jeff Davis]

> Keep in mind that there's also psycopg and PyGreSql, as far as Python

interfaces go.

pg.py and pgdb.py are both part of PyGreSQL. pg.py is the more low-level
interface, closer to a wrapper of libpq (but with lots of helper
functions to make it natural to use in python), and pgdb.py is
PyGreSQL's DBAPI-2.0-compliant interface, which is compatible with other
interfaces in python (so you could swap out another DB for PostgreSQL
without code changes, ideally).

pgdb.py, in compliance with the DBAPI-2.0 spec, does things like match
data types up by using the system catalogs (so you don't have to convert
from text) and has even more features to make it even more natural to
use with python. However, with each version change, pgdb.py needs to be
updated to match the current version of the postgres catalogs, which is
the problem the poster ran into. I think it's supposed to be similar to
JDBC in some respects.

I usually use pg.py, so I might have some details wrong about pgdb.py.

Regards,
Jeff Davis
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[Tom Lane]

"Manuel Tejada" <ma*****@terra. com.pe> writes:

But now when I input the same sintaxis with the new Installation(Po stgreSQL
7.4.1), I get an error when I enter rhe four line: _pg.error: ERROR: non exist the column "typprtlen"

I believe this indicates you're using an old version of the PyGreSQL
module. typprtlen disappeared from the pg_type system catalog several
releases back. There is updated PyGreSQL code out there, but I'm not
very sure where --- have you looked at gborg.postgresq l.org?

regards, tom lane

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[Manuel Tejada]

Old version of the PyGreSQL?

Remember I said that I made un apgrade to PostgreSQL version 7.4.1.
One of rpms I used to upgrade is the postgresql-python-7.4.1-1PGDG.i386.rpm.
I suppose that this come with the last version of PyGreSQL.

The README file in /usr/share/doc/postgresql-python-7.4.1 tells that the
module PyGreSQL is version 3.4. This version is the last according to
ftp://ftp.druid.net/pub/distrib/

When I use the module C or the module pg.py of PyGreSQL to connect with
PostgreSQL, they work fine.

But I would like to use the pgdb.py too

----- Original Message -----
From: "Tom Lane" <tg*@sss.pgh.pa .us>
To: "Manuel Tejada" <ma*****@terra. com.pe>
Cc: <pg***********@ postgresql.org>
Sent: Friday, January 30, 2004 11:41 PM
Subject: Re: [GENERAL] PostgreSQL 7.4.1 and pgdb.py

"Manuel Tejada" <ma*****@terra. com.pe> writes:

But now when I input the same sintaxis with the new Installation(Po stgreSQL 7.4.1), I get an error when I enter rhe four line:

_pg.error: ERROR: non exist the column "typprtlen"

I believe this indicates you're using an old version of the PyGreSQL
module. typprtlen disappeared from the pg_type system catalog several
releases back. There is updated PyGreSQL code out there, but I'm not
very sure where --- have you looked at gborg.postgresq l.org?

regards, tom lane

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[Gaetano Mendola]

Manuel Tejada wrote:

import pgdb
dbConnect = pgdb.connect(ds n='localhost:or acle', user='manuel',
password='')
cursor = dbConnect.curso r()
cursor.exec ute("select * from address")

Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/usr/lib/python2.2/site-packages/pgdb.py", line 189, in execute
self.executeman y(operation, (params,))
File "/usr/lib/python2.2/site-packages/pgdb.py", line 221, in executemany
desc = type[1:2]+self ._cache.getdesc r(typ[2])
File "/usr/lib/python2.2/site-packages/pgdb.py", line 149, in getdescr
self ._source.execut e(
_pg.error: ERROR: non exist the column "typprtlen"
------------------

This is a really old problem already solved on 7.3 see this my post:

http://archives.postgresql.org/pgsql...2/msg00082.php

I'm checking that my 7.4.1 installation is affected by the same
problem. I don't understand how this could happen that a modification
made on a 7.3 was not ported to 7.4

For the moment what you can do is substitute this select:

"SELECT typname, typprtlen, typlen "
"FROM pg_type WHERE oid = %s" % oid

inside the file pgdb.py with this one:

"SELECT typname, 4, typlen "
"FROM pg_type WHERE oid = %s" % oid

just to not break all file.

I'm not able to look at CVS to see where the modification was lost.

Regards
Gaetano Mendola

[Gaetano Mendola]

Tom Lane wrote:

"Manuel Tejada" <ma*****@terra. com.pe> writes:

But now when I input the same sintaxis with the new Installation(Po stgreSQL
7.4.1), I get an error when I enter rhe four line:

_pg.error: ERROR: non exist the column "typprtlen"

I believe this indicates you're using an old version of the PyGreSQL
module. typprtlen disappeared from the pg_type system catalog several
releases back. There is updated PyGreSQL code out there, but I'm not
very sure where --- have you looked at gborg.postgresq l.org?

Unfortunately the pgdb.py is wrong and is shipped with

postgresql-python-7.4.1-1PGDG.i386.rpm

this problem was solved already on 7.3

look this:

http://archives.postgresql.org/pgsql...2/msg00082.php

something did wrong during the SRPM file building for the 7.4.1

Is a good idea look how this happen.


Regards
Gaetano Mendola

[Manuel Tejada]

Thank you very much Gaetano

I edited the pgdb.py file setting "4" instead of "typprtlen" .
Now I am able to connect to PostgreSQL using pgdb.py.

Just for curiosity, Can I set to -1 too as Gerhard Haring told to you?
----- Original Message -----
From: "Gaetano Mendola" <me*****@bigfoo t.com>
Newsgroups: comp.databases. postgresql.gene ral
Cc: "Manuel Tejada" <ma*****@terra. com.pe>
Sent: Sunday, February 01, 2004 4:48 PM
Subject: Re: PostgreSQL 7.4.1 and pgdb.py

Manuel Tejada wrote:

>import pgdb
>dbConnect = pgdb.connect(ds n='localhost:or acle', user='manuel',

password='')

>cursor = dbConnect.curso r()
>cursor.exec ute("select * from address")

Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/usr/lib/python2.2/site-packages/pgdb.py", line 189, in execute
self.executeman y(operation, (params,))
File "/usr/lib/python2.2/site-packages/pgdb.py", line 221, in executemany desc = type[1:2]+self ._cache.getdesc r(typ[2])
File "/usr/lib/python2.2/site-packages/pgdb.py", line 149, in getdescr self ._source.execut e(
_pg.error: ERROR: non exist the column "typprtlen"
------------------

This is a really old problem already solved on 7.3 see this my post:

http://archives.postgresql.org/pgsql...2/msg00082.php

I'm checking that my 7.4.1 installation is affected by the same
problem. I don't understand how this could happen that a modification
made on a 7.3 was not ported to 7.4

For the moment what you can do is substitute this select:

"SELECT typname, typprtlen, typlen "
"FROM pg_type WHERE oid = %s" % oid

inside the file pgdb.py with this one:

"SELECT typname, 4, typlen "
"FROM pg_type WHERE oid = %s" % oid

just to not break all file.

I'm not able to look at CVS to see where the modification was lost.

Regards
Gaetano Mendola

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[Gaetano Mendola]

Manuel Tejada wrote:

Thank you very much Gaetano

I edited the pgdb.py file setting "4" instead of "typprtlen" .
Now I am able to connect to PostgreSQL using pgdb.py.

Just for curiosity, Can I set to -1 too as Gerhard Haring told to you?

I think yes, I really didn't dig on it to see the usage of that
value.
Regards
Gaetano Mendola