Thanks again for your post, and my sincere apologies for the delay in
writing (I've been off and then had to sort out some other stuff which
required all of my limited attention!).
Thanks also to the off-list help from David Rushby.
His advice which sort of worked was basically:
Using a database interface that allows you to take
advantage of prepared statements and bound parameters,
as in:
cur.execute(update table_1 set blob_field_1 = ?
where other_field_1 = ?, ('blob string value', 'other
field value'))
This was a slightly different python syntax to that which I was using, and
seems to work - but only when using it straight from Python. I can run this
absolutely fine (even using gvib!) from the python instance in the Plone
installation (Plone\Python\python.exe). There are absolutely no errors, and
it updates the field.
However, copying the function almost exactly (just inserting a self
parameter before the two notes/key parameters .. or even trying it without)
does not work. When I call this function, Plone freezes - no errors,
nothing, just everything freezes up (there's nothing I can see in the log
files apart from it calling the page).
I don't know if this is of any significance, but when this happens, for any
calls to a page served by Plone, the browser tries to open the page, but
nothing happens, no page not found errors, etc, it just keeps trying. Once
Plone has been stopped, then the page not found appears. I doubt its of any
use, but you can't have too much info!!
Anyway, the function in the external method is:
def updateEntityNotes(self,notes,entKey):
try:
dbCon = gvib.connect(theDB, userName, userPass)
cur=dbCon.cursor()
cur.execute(UPDATE ENTITY SET EN_NOTES=? WHERE
EN_KEY=?,(notes,int(entKey)))
dbCon.commit()
return 'ok'
except:
return 'bError:/b Sorry, your request could not be processed
correctly.br '+str(traceback.format_exception(sys.exc_type, sys.exc_value,
sys.exc_traceback))
And it is called with a dtml-let call (so the result can be used):
dtml-let err=updateEntityNotes(theNotes,theKey)
(theNotes and theKey have already been subject to calls to be str() and
int() respectively).
I just tested the interface to this from Plone, removing any database access
at all, and just returning a random statement, and it works fine. So Plone
is accessing the external method, there are no imported functions used that
aren't used in other external methods, so it just seems to be executing the
cur.execute() statement. Without the dbCon.commit(), Plone still crashes.
Can anyone tell me why the actual python instance that came with Plone can
do this fine, but Plone itself can't?
Kind regards, and thanks once again to everyone who has helped me.
Ashley
- Original Message -
From: bobb [EMAIL PROTECTED]
To: Ashley Lloyd [EMAIL PROTECTED]; zope-db@zope.org
Sent: Friday, August 05, 2005 6:39 PM
Subject: Re: [Zope-DB] Zope/Plone, interbase, and blob fields
- Original Message -
From: Ashley Lloyd [EMAIL PROTECTED]
To: zope-db@zope.org
Sent: Friday, August 05, 2005 6:55 AM
Subject: [Zope-DB] Zope/Plone, interbase, and blob fields
Apologies if this appears twice - I initially sent from the wrong
address!!
Hi, I've been having trouble updating BLOB (subtype text) fields from
Zope.
I've a table with several fields, one of which is a blob. Creating a
record
works fine, but when I attempt to update a record, I get an error.
Initially
I used gvib, but recently (thanks to a lot of help from another list) I
changed to kinterbasdbDA, and I still get errors.
The errors I get are as follows:
Error Type ProgrammingError
Error Value (-413, 'execute.isc_dsql_execute: conversion error from
string
BLOB. ')
Error Trace Traceback (most recent call last):
File C:\Program
Files\ESOPPlone\Zope\lib\python\DocumentTemplate\DT_Try.py, line 149,
in
render_try_except
result = render_blocks(self.section, md)
File C:\Program
Files\ESOPPlone\Zope\lib\python\DocumentTemplate\DT_Util.py, line 201,
in
eval
return eval(code, d)
File , line 2, in f
File C:\Program Files\ESOPPlone\Zope\lib\python\Shared\DC\ZRDB\DA.py,
line
428, in __call__
else: result=DB__.query(query, self.max_rows_)
File C:\Program
Files\ESOPPlone\Zope\lib\python\Products\kinterbasdbDA\db.py, line 198,
in
query
self.cursor.execute(src)
File C:\Program
Files\ESOPPlone\Zope\lib\python\Products\kinterbasdbDA\kinterbasdb\__init__.
py, line 585, in execute
res = _kinterbasdb.execute(self._C_cursor, sql, params)
ProgrammingError: (-413, 'execute.isc_dsql_execute: conversion error
from
string BLOB. ')
I also get a similar error (same value type) when just testing the SQL
method in the ZMI, even when the SQL that the method generates is just:
UPDATE ENTITY
SET EN_NOTES = 'Hello world'
WHERE EN_KEY = 12
The metatata of the table has the notes field definition as:
EN_NOTES BLOB SUB_TYPE 1 SEGMENT SIZE 80,
Maybe you
