[Pypgsql-users] select following an insert fails in getTypeInfo()

[Greg F. <gr...@gr...>]

Hi,

   I've run into problems with a script of mine that used to work a few 
months back. I've
apt-get dist-upgraded my debian sarge box since so I'd guess it's either 
a new postgresql
or a new python-pgsql. I've tried using pypgsql 2.4.0-7 & 2.4.0-5 from 
debian, with postgresl
versions v7.5.15 and 7.4.7-6sarge1.

   The script does an Insert into a table, then attempts to read entries 
(there should only be one)
from that table for the key value i've just inserted.

here's some code snippets.

    try:
        cur.execute("INSERT INTO xmltv.channels (chan_id) VALUES ( '%s' 
)" % channel["channel_id"] )
        cOid = getChannelOid( channel["channel_id"] )


def getChannelOid( cOID):
    try:
        cur.execute( "SELECT chan_oid FROM xmltv.channels where 
chan_id='%s'" % cOID )

The library barfs on the SELECT statement, an error occurs and the 
library tries to rollback the transaction.
The item it is trying to do a select on has definately been added to the 
table because if I do a db.commit() here
and abort I can see it still in the database. Also if I enter the 
commands from the postgresql.log into psql manually
it works and returns the correct result.

Here's the python traceback of the failed select:

  File "./parse.py", line 63, in getChannelOid
    cur.execute( "SELECT chan_oid FROM xmltv.channels where chan_id=4" )
  File "/usr/lib/python2.3/site-packages/pyPgSQL/PgSQL.py", line 3086, 
in execute
    self.__makedesc__()
  File "/usr/lib/python2.3/site-packages/pyPgSQL/PgSQL.py", line 2826, 
in __makedesc__
    _tn, _pl, _ia, _bt = _cache.getTypeInfo(_typ)
  File "/usr/lib/python2.3/site-packages/pyPgSQL/PgSQL.py", line 886, in 
getTypeInfo
    raise Warning, self.__conn.notices.pop()
libpq.Warning: LOG:  statement: BEGIN WORK


 From the postgresql.log I can see (just before the rollback)

 STATEMENT:  SELECT typname, -1 , typelem FROM pg_type WHERE oid = 20
2006-03-28 14:45:42 [32097] DEBUG:  StartTransactionCommand
STATEMENT:  ROLLBACK WORK
2006-03-28 14:45:42 [32097] LOG:  statement: ROLLBACK WORK

Is -1 a valid input into this SELECT?

thanks a lot for any help you can provide,

     Greg