What version are you using?
This is what I get:
>>> db=DAL()
>>> product = db.define_table('product', Field('cost1'), Field('cost2'),
Field('total', compute = lambda r: r['cost1'] + r['cost2']))
>>> product.insert(cost1=10, cost2=20)
1
>>> p = db.product(1)
>>> p.update_record(cost1=5)
<Row {'update_record': <gluon.dal.RecordUpdater object at 0x1019bc250>,
'cost1': 5, 'cost2': '20', 'total': '30', 'id': 1, 'delete_record':
<gluon.dal.RecordDeleter object at 0x1019bc290>}>
>>> print db.product[1].total
30
On Saturday, 22 September 2012 20:36:44 UTC-5, VP wrote:
>
> I figured out what I would call a bug.
>
> I'll give an example:
>
> Let's say we have this table:
>
>
> product = db.define_table('product', Field('cost1'), Field('cost2'),
> Field('total', compute = lambda r: r['cost1'] + r['cost2']))
>
>
> And if you do this:
>
> product.insert(cost1=10, cost2=20)
> p = db.product(1)
> p.update_record(cost1=5)
>
>
> This update won't work. What is worse is that it fails silently. The
> reason it won't work is that the row input of the lambda does not have
> "cost2" in it.
>
> If, however, you do this:
>
> p.update_record(cost1=5, cost2=p.cost2)
>
> Then it will work, because now the parameter r (i.e. the row) has both
> cost1 and cost2.
>
>
>
> I think it'll be a little tricky for you to fix this, because you probably
> want update to have only relevant fields so that saving to the database is
> effective. However, this behavior clearly is not desirable.
>
>
>
> On Saturday, September 22, 2012 5:23:43 PM UTC-5, Massimo Di Pierro wrote:
>>
>> Can you show us an example?
>>
>> computed fields usually do not work when there is not enough information
>> to compute. The information must be in the arguments of update_record or
>> update. It will not retrive the info from the database.
>>
>>
>>
>>
>> On Saturday, 22 September 2012 15:43:59 UTC-5, VP wrote:
>>>
>>> - sqlite
>>> - 2 compute fields do not seem to get call on update using both
>>> update_record and db().update
>>> - They do work on crud/form updates though.
>>>
>>
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