Re: [SQLObject] a general db design quesiton

[Gregor H. <gh...@gr...>]

Daniel Fetchinson schrieb:
>> A forth table that has four columns: its own primary key; three
>> foreign keys, one for each table. It is comparable to a many-to-many
>> relationship, but with three tables instead of just two.
>>
>> class FourthTable(SQLObject):
>>     first = ForeignKey("FirstTable")
>>     second = ForeignKey("SecondTable")
>>     third = ForeignKey("ThirdTable")
>>
>> Not sure why you would want to do this. Perhaps there are relations
>> between any two table that should be flushed out first?
> 
> Thanks a lot for the reply! The reason I want to do this is a kind of
> commenting system. There are 3 types of objects with totally different
> rows and methods each in its own table. But they share the feature
> that they can all be commented on. Comments are stored in a separate
> table but that table has to have a row which refers to the object the
> given comment belongs to. And this object can be in any of the 3
> tables.
> 
> So how would I connect a comment to the object it refers?
> 


I use so called SubObjects for excactly this purpose:

http://paste.turbogears.org/paste/1684

--
Greg