[Building Sakai] Does anyone have good DB-Diagrams for Sakai 2.x?

[Matthew Jones]

I'd agree the foreign keys within a tool (like Samigo, Gradebook) are
probably good, but there's no links across tools. For instance nothing that
relates User or Site (context) to Gradebook, Assessment, Assignment, Forum,
etc. in the database as an explicit foreign key. This seems like it could
make figuring out relationships difficult, but it also has the side benefit
of not forcing data to need to be removed when the parent is removed. For
instance in Sakai if a user or site is deleted, the content they created
isn't deleted, they can just be re-added and it will all show up again.

It's possible that someone may want to delete a site and have it cascade
delete everything related to that site, but this just isn't possible with
how Sakai is designed. I guess that's a that's a possible negative side
effect of not knowing how some of these high level things link together,
easy recovery, but nothing is cleaned up. If this was desired, this work
would be up to a developer, and would likely be a lot of work.

In addition, some older tools store their metadata as 'Nosql-style' XML
blobs, so there was no way to do foreign key relationships anyway.


On Wed, Jan 9, 2013 at 10:16 AM, Sam Ottenhoff <ottenhoff at longsight.com>wrote:

> Sakai has explicit foreign keys; I'm not sure what Chuck's problem was.
>  Using DbVisualizer on a proper Sakai database will show lots of foreign
> key relationships.
>
> Using MySQL *without* InnoDB enabled means that your database was probably
> created using MyISAM tables.  MyISAM tables do not support foreign keys.
>
> --Sam
>
>
> On Wed, Jan 9, 2013 at 6:50 AM, Jean-Francois Leveque <
> jean-francois.leveque at upmc.fr> wrote:
>
>> Hi Chuck,
>>
>> Do you mean foreign keys are handled by the app instead of being part of
>> the DDL, when writing about "lack of explicit foreign keys"?
>>
>> If it's the case, shouldn't we improve the DDL?
>>
>> Thanks,
>>
>> J-F
>>
>> On 22/03/2012 13:23, csev wrote:
>> > Thanks to everyone with the db visualizer help.
>> >
>> > Of course I dumped Sakai in and the lack of explicit foreign keys kept
>> > the model quite boring.
>> >
>> > So I did it by hand in Keynote for my lecture.
>> >
>> > Lecture went well.
>> >
>> > Again, thanks.
>> >
>> > /Chuck
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