I've got the same problem. I have a field with type decimal(12,4), I can
add a number to this field but not subtract. So instead of
db(db.client_service.id == id).update(minutes_done =
db.client_service.minutes_done
- minutes)
I have to write
minutes = -minutes
db(db.client_service.id == id).update(minutes_done =
db.client_service.minutes_done
+ minutes)
as a workaround. that makes the code much harder to read. I see no reason
why the first query should not be possible. Any chance this will be fixed?
Alex
Am Mittwoch, 6. März 2013 19:30:22 UTC+1 schrieb Cliff Kachinske:
>
> I see what the code is doing.
>
> Would this work?
>
> if db._adapter.driver.__name__ in ('sqlite'): # maybe others?
> if self.type in ('integer','bigint'):
> result_type = 'integer'
> elif self.type in ['date','time','datetime','double','float']:
> result_type = 'double'
> else:
> raise SyntaxError("subtraction operation not supported for
> type")
> else:
> result_type = self.type
>
>
>
> On Wednesday, March 6, 2013 11:55:20 AM UTC-5, Massimo Di Pierro wrote:
>>
>> According to the code:
>>
>> if self.type in ('integer','bigint'):
>> result_type = 'integer'
>> elif self.type in ['date','time','datetime','double','float']:
>> result_type = 'double'
>> else:
>> raise SyntaxError("subtraction operation not supported for
>> type")
>>
>> what is the type of db.production_jobs.quantity_on_hand?
>>
>> On Wednesday, 6 March 2013 08:45:20 UTC-6, Cliff Kachinske wrote:
>>>
>>> V 2.4.2
>>>
>>> Apparently I can add a negative number in an update expression but I cannot
>>> subtract a positive number.
>>>
>>>
>>> Snippet:
>>>
>>> delta = new_allocation - record.quantity_allocated
>>> db(db.production_jobs.id==record.production_job_id).update(
>>> quantity_on_hand=db.production_jobs.quantity_on_hand - delta #
>>> subtraction. DAL will not like it
>>> )
>>>
>>> Snippet raises this exception:
>>>
>>> File
>>> "/home/cjk/pybin/w-2-4-2/web2py/applications/Inventory/controllers/customer_order_product_lots.py",
>>> line 70, in update_lot_record
>>> quantity_on_hand=db.production_jobs.quantity_on_hand - delta
>>> File "/home/cjk/pybin/w-2-4-2/web2py/gluon/dal.py", line 8820, in __sub__
>>> raise SyntaxError("subtraction operation not supported for type")
>>> SyntaxError: subtraction operation not supported for type
>>>
>>> Hackish workaround:
>>>
>>> delta = -(new_allocation - record.quantity_allocated) # flip value to
>>> negative
>>> db(db.production_jobs.id==record.production_job_id).update(
>>> quantity_on_hand=db.production_jobs.quantity_on_hand + delta # add
>>> negative number. DAL okay with this
>>> )
>>>
>>>
>>> Is this the expected behavior?
>>>
>>> Or am I missing something?
>>>
>>>
>>>
--
---
You received this message because you are subscribed to the Google Groups
"web2py-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to web2py+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
