FYI : putting all the fields in one table will result to multiple columns
...
On Tuesday, September 11, 2012 5:31:37 PM UTC+2, Anthony wrote:
>
> Why do you want a one-to-one relation? Can't you just put all the fields
> in one table?
>
> Anthony
>
> On Tuesday, September 11, 2012 9:23:16 AM UTC-4, martzi wrote:
>>
>> Unique = True, has probably no effect. see below.
>> ...
>> >>> db = DAL('sqlite://storage.db')
>> >>> person = db.define_table('person', Field('name'))
>> >>> bodypart = db.define_table('bodypart', Field('name'), Field('owner',
>> 'reference person', unique=True)) #unique= True seems to have no effect
>> >>> pid = person.insert(name='Sid')
>> >>> bpid = bodypart.insert(name='arms', owner= pid) #pid = 1
>> >>> bodypart(bpid).owner #bpid = 1, first insertion of owner as 1
>> 1
>> >>> bpid = bodypart.insert(name='mouth', owner= pid) # multiple entries
>> not caught, pid is still 1
>> >>> bodypart(bpid).owner #bpid = 2, second insertion of owner as 1 AGAIN
>> 1
>>
>> On Tuesday, September 11, 2012 2:22:09 PM UTC+2, villas wrote:
>>>
>>> I am quite familiar with cascade; I just couldn't figure out how it
>>> could assist you.
>>>
>>> In my opinion, Field('....','reference other_table', unique=True)
>>> should be supported and work. Maybe you added the constraint later and the
>>> DB didn't accept it because you already had duplicated field contents.
>>>
>>> In any case, even if unique=True is not working for the moment, then a
>>> work-around would be to make a unique index on the field yourself. You'll
>>> have to handle exceptions when the insert/update fails due to duplicate
>>> keys.
>>>
>>>
>>>
>>>
>>> On Tuesday, September 11, 2012 12:48:49 PM UTC+1, martzi wrote:
>>>>
>>>> Thanks for the reply. But if you meant Field('....','reference
>>>> other_table', unique=True), I have tried that with failure, i am still
>>>> having a one-to-many relation. FYI: Regarding CASCADE, an ondelete
>>>> cascade
>>>> causes deletion of all referred data.
>>>>
>>>> On Tuesday, September 11, 2012 1:37:59 PM UTC+2, villas wrote:
>>>>>
>>>>> I may be wrong, but I do not think Cascade could assist you with
>>>>> enforcing a 1-1 relationship.
>>>>> Maybe making the foreign key field unique would help?
>>>>>
>>>>>
>>>>> On Monday, September 10, 2012 11:45:28 AM UTC+1, martzi wrote:
>>>>>>
>>>>>> Hi,
>>>>>> I wonder if there a way to enforce a one to one relationship with
>>>>>> Cascade via web2py DAL API. ???
>>>>>>
>>>>>
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