Re: postgres inheritance

> Mike,
>
> Thank you for your support. I have momentarily hacked tedia2sql perl
> script to add inheritance to postgres tables when a class is found to
> have an operation named "inherits". Its type is used to refer to the
> table name it inherits from. Ugly, but it works for the timing
> deadline I am currently on.
>
> Problems:
>
> 1. The correct way to interpret inheritance is, as I understand it,
> make use of the "Generalization" association type. Have digged into
> the source and guess the correct approach is to add the inheritance
> info into the class definition when traversing through the association
> nodes (a function called generateAssocSqlFromNodeList if I'm not
> mistaken).
>
> 2. On complex diagrams, the ordering of table definitions will
> eventually upset postgres at import time (an inheriting table has to
> be defined after the table it inherits from). Not sure if Dia's object
> Z-order might help, but safest solution I guess is to build a
> parent-child relationship tree during diagram scanning.
>
> Unfortunately am not very skillfull on Perl, but I am more than happy
> to help implement and document it if there's interest. Let me know if
> you'd like me to forward the temporary patch.
>
> best regards
> albert
>
> 2007/4/18, Mike Ginou <mike@...>:
>> Albert,
>>
>> Unfortunately, I don't have any experience with inheritence in an RDBMS.
>> Therefore, I don't think I'm in a good position to add this feature.
>>
>> If you're willing to dig into it yourself, I would be more than happy to
>> offer suggestions and to answer any questions you might have.
>>
>> Cheers,
>> Mike
>>
>> albert wrote:
>> > Hi all,
>> >
>> > I've been searching through multiple sites including this official
>> > mailing list, on how to implement postgres table inheritance using
>> > tedia2sql. There's some mentions about this feature being implemented,
>> > but sadly enough, grepping through a fresh cvs checked-out revision
>> > has returned me no results.
>> >
>> > I'm looking for a way to represent this postgres definition:
>> >
>> > CREATE TABLE a (...) with oids;
>> > CREATE TABLE b (...) inherits a;
>> >
>> > on a dia diagram which tedia2sql can understand properly.
>> >
>> > best regards
>> >
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