Thank you so much for your reply. That took care of everything.
Thank you very much for the tips. I know the code is very rough. I had just
started on it when I ran into this problem, and I'm still fairly new to
web2py and python.
Thanks again for your help.
Joel Robinson
On Thursday, June 7, 2012 3:34:46 PM UTC-5, Anthony wrote:
>
> Two problems:
>
> 1. You are using partnum as a GET variable, but it is also the name of
> one of the form fields, so when you submit the form, there is a "partnum"
> in both the GET and the POST variables. When the same variable appears in
> both the GET and POST variables, web2py puts them in a list in
> request.vars
> -- so, in this case, upon form submission, request.vars.partnum is
> ['12345', '12345'] instead of just '12345'. To avoid that problem, you
> should refer specifically to request.get_vars.partnum instead of
> request.vars.partnum.
> 2. Issue #1 caused your query to return no results, but you don't have
> any logic to check for no results (which would be a problem even without
> issue #1), which is why you got an error ticket.
>
> Your code also includes some unnecessary checks and variable assignments.
> Here's a much simpler version of the code:
>
> def update_inventory():
> if request.get_vars.partnum:
> row = db(db.invent.partnum == request.get_vars.partnum).select().
> first()
> return dict(record=crud.update(db.invent, row.id) if row
> else 'Part #%s not found' % request.get_vars.partnum)
> else:
> return dict(record="No part number. URL should read
> update_inventory?part=12345")
>
> Note, I removed the check for duplicates:
>
> # check to make sure there are no double entries in database
> if(len(rows) > 1):
> record = "Database Error"
> return dict(record=record)
>
> That shouldn't be necessary, because in your model definition, you have:
>
> Field('partnum', unique=True),
>
> Setting unique=True tells the database not to allow duplicates, so if you
> try to enter a duplicate, you'll get an operational error from the
> database. However, getting an error from the database isn't a friendly user
> experience, so in addition to setting unique=True, you should also add an
> IS_NOT_IN_DB
> validator<http://web2py.com/books/default/chapter/29/7#Database-validators>to
> the field -- the validator will be enforced at the form level and will
> result in a friendly error message being displayed on the form when a
> duplicate value is submitted:
>
> Field('partnum', unique=True,
> requires=IS_NOT_IN_DB(db, 'invent.partnum')),
>
> Anthony
>
> On Thursday, June 7, 2012 3:33:51 PM UTC-4, Joel Robinson wrote:
>>
>> Here's the code in a web2py module. You'll have to enter a few things in
>> the database with the
>> enter_inventory page.
>>
>> To see the problem enter, for example, part number 12345 and a quantity
>> of 3 on the enter_inventory page.
>> Once that is entered you can enter the following URL:
>> http://localhost:8000/GTV/default/update_inventory?partnum=12345
>>
>> the page will initially come up correctly. But if you change the quantity
>> from 3 to 2, for example, and then
>> hit the submit button, you will get an error.
>>
>> Thanks again for you help with this
>>
>> Joel Robinson
>>
>>
>> On Thursday, June 7, 2012 12:38:46 PM UTC-5, Anthony wrote:
>>>
>>> Yeah, I think you'll have to show more code.
>>>
>>> On Thursday, June 7, 2012 12:58:45 PM UTC-4, Joel Robinson wrote:
>>>>
>>>> Thanks for the reply. I tried you sugestion but still no joy. I haven't
>>>> included all the code
>>>> so that the examples as simple as possible. I can try to attach some of
>>>> my code and send it
>>>> to you if you wish.
>>>>
>>>> If you add some code such as:
>>>> else :
>>>> record = 'No part number URL should read
>>>> "update_inventory?partnum=something"'
>>>> return dict(record=record)
>>>>
>>>> then it returns that message when you submit an update, but the
>>>> database is still not being updated.
>>>>
>>>>
>>>> On Thursday, June 7, 2012 11:11:41 AM UTC-5, Anthony wrote:
>>>>>
>>>>> What are you returning in case no rows are found? Also, you can
>>>>> instead do:
>>>>>
>>>>> row = db(db.invent.partnum == request.vars.partnum).select().first()
>>>>> if row:
>>>>> etc.
>>>>>
>>>>> .first() returns the first row or None if there are no records.
>>>>>
>>>>> Anthony
>>>>>
>>>>> On Thursday, June 7, 2012 10:49:54 AM UTC-4, Joel Robinson wrote:
>>>>>>
>>>>>> Thanks for the reply, but its still not working correctly. I changed
>>>>>> the code to the following:
>>>>>>
>>>>>> if rows:
>>>>>> row = rows[0]
>>>>>> record = crud.update(db.invent, row.id )
>>>>>> return dict(record=record)
>>>>>>
>>>>>> with a URL like:
>>>>>>
>>>>>> http://localhost:8000/GeorgesTV/qrinv/update_inventory?partnum=LAMP-4
>>>>>>
>>>>>> I will get the correct web page, but when I change a value and hit
>>>>>> the submit button I just get sent to
>>>>>> a page that says "None". If I reload the page the values are
>>>>>> unchanged. Nothing was updated.
>>>>>>
>>>>>> Joel Robinson
>>>>>>
>>>>>> On Thursday, June 7, 2012 9:33:57 AM UTC-5, Anthony wrote:
>>>>>>>
>>>>>>> Same problem -- everything has to go inside your "if rows:" block --
>>>>>>> don't attempt to create a crud.update form if no rows have been
>>>>>>> returned.
>>>>>>>
>>>>>>> Anthony
>>>>>>>
>>>>>>> On Thursday, June 7, 2012 10:30:17 AM UTC-4, Joel Robinson wrote:
>>>>>>>>
>>>>>>>> Thanks for the reply. I tried your sugestion but am still getting
>>>>>>>> an error, though a different one:
>>>>>>>>
>>>>>>>> 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 136, 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 131, in update_inventory
>>>>>>>> record = crud.update(db.invent, row.id )
>>>>>>>> UnboundLocalError: local variable 'row' referenced before assignment
>>>>>>>>
>>>>>>>> Just to be clear the page is coming up initialy. This error only
>>>>>>>> happens when I click
>>>>>>>> on the submit button. Thanks again for your help.
>>>>>>>>
>>>>>>>> Joel Robinson
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Wednesday, June 6, 2012 4:14:29 PM UTC-5, Massimo Di Pierro
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> 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
>>>>>>>>>>
>>>>>>>>>>
