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Re: UU database: problem tables
On a related note, problem (just like any other object actually)
can belong to more then one topic, more then one test, etc.
Same is true for topic->subtopic relationship.
On the other hand, there is 0-1:1 relationship between course and
topic. I.E. like we talked about earlier, course is just an administrative
unit, wrapping single top-level topic.
Ilya A. Volynets-Evenbakh wrote:
> Alexey Parshin wrote:
>
>> Alexey Parshin wrote:
>> > Actually,
>> > I expected that single problem may be offered to many students,
>> and
>> > every student may have personal solution with personal access and
>> > personal status.
>> That is correct. However, status is not part of ACL entry. That is why
>> they have to be separate
>> tables. Basically status may stay ( i.e. for scoring purposes)
>> even after
>> student loses any access
>> to the problem.
>>
>> Interesting. In this case,
>> 1) The present structure, one problem -> many solutions(one per person
>> or even many per person) is correct, isn't it? Please, confirm.
>>
> I actually didn't think about more then one solutions
> per-person+problem, but I guess it is actually possible.
> At least I don't see any good reason to limit database from allowing it.
>
>> 2) Status isn't a part of the access and may stay even after a person
>> lost the access to the object. It may be: not started, working on,
>> completed, failed.. Status may be a part of ACL only because it's
>> convenient - we don't have to create a separate set of status tables
>> for topic, problem, course etc..
>>
> Except status _is_ different, and may stay after access is revoked. So
> it has to be in different tables.
>
>
--
Ilya A. Volynets-Evenbakh
Total Knowledge. CTO
http://www.total-knowledge.com