Looks like the error is at
row = rows[0]
because rows is empty (no records matching query). You need a check like
if rows:
row = rows[0]
On Wednesday, 6 June 2012 12:19:14 UTC-5, Joel Robinson wrote:
>
> First, let me give some background on what I've been trying to do. We
> wanted to set up an inventory system using QR codes which would be put on
> stickers on our stock and then scaned with smartphone when removing
> inventory bring up the appropiate web page. The QR code should contain
> something like:
>
> http://GeorgesTV/qrinv/update_inventory?partnum=12345
>
> and the following is the code I wrote for update_inventory:
>
> rows = db(db.invent.partnum == request.vars.partnum).select()
> # change rows object to row object
> row = rows[0]
>
> # display queried object
> record = crud.update(db.invent, row.id)
> return dict(record=record)
>
> initialy it would work fine it would run the query and pull up the correct
> record but
> if I tried to update the record I would get the folling error:
>
>
> Traceback (most recent call last):
> File "/home/joel/Source/web2py/gluon/restricted.py", line 205, in restricted
> exec ccode in environment
> File "/home/joel/Source/web2py/applications/GeorgesTV/controllers/qrinv.py"
> <http://127.0.0.1:8000/admin/default/edit/GeorgesTV/controllers/qrinv.py>,
> line 123, in <module>
> File "/home/joel/Source/web2py/gluon/globals.py", line 173, in <lambda>
> self._caller = lambda f: f()
> File "/home/joel/Source/web2py/applications/GeorgesTV/controllers/qrinv.py"
> <http://127.0.0.1:8000/admin/default/edit/GeorgesTV/controllers/qrinv.py>,
> line 116, in update_inventory
> row = rows[0]
> File "/home/joel/Source/web2py/gluon/dal.py", line 7755, in __getitem__
> row = self.records[i]
> IndexError: list index out of range
>
> I thought maybe the request variable wasn't getting passed correctly when
> updated so I made the following change:
>
> session.partnum = request.vars.partnum
> rows = db(db.invent.partnum == session.partnum).select()
>
> which didn't help either, but I then noticed that if I tried to pull up the
> update_inventory page now without the query string
> it would come up since session varible was already set and it would update
> correctly!
>
> I was eventualy able to get it work more or less how I wanted by writing a
> page whose only function was to take the
> query string set a session variable and then redirect you to the
> update_inventory page. But I worry that using session varibles
> may cause unforseen problems eventualy.
>
> So what I would like to know, is this a bug I've found or am I going about
> doing this incorrectly? Could someone explains
> what happens when you use crud.update and why I get this error when I try to
> use query strings?
>
> Thanks in advance for your help.
>
> Joel Robinson
>
>
