Re: Foreign Key Problems
Date: 12 Aug 1994 13:33:47 GMT
Message-ID: <rayo.334.0_at_ontko.com>
>> > Just a little technical note about FK constraints in V6. It's true
>> > that they're not enforced in DML, but the actually ARE enforced in DDL.
>> > Just try DROPping the Dept table if there's a FK pointing to it from the
>> > Emp table and you'll see for yourself.
>>
>> Duh :-) This was one of the stupidest things Oracle EVER did, IMHO.
>>
>> They implemented the SYNTAX of this feature in V6 so they could claim
>> SYNTACTICAL compatibility with the ANSI SQL Referential Integrity
>> Enhancement (1989) and then didn't implement the functional capability so
>> that it would useful in any way, shape or form. I would like to know
>> exactly WHAT good comes of enforcing the constraints on the table
>> definitions but not on the data????
>>
- omitted
>>
>> Now, so that I won't get flamed for not saying SOMETHING nice, I will say
>> that V7 has an EXCELLENT referential constraints implementation that works
>> and works well. So, when they finally got around to it, they indeed put
>> in a mighty fine "engine".
>>
>Agreed. The reason Oracle _probably_ (imnsho) did it that way was:
>1) the marketing types wanted that compatibility statement; and
>2) it gave a growth path so that at least the database could be built
> properly
>3) Sql*Forms could create it's own triggers based upon them. This is why
> ddl probably enforces them... so that the form triggers remain
> consistant.
And not only SQL*forms. This has been quite useful for other application development and case tools to share information about the structure of the data in the database.
Ray Ontko rayo_at_ontko.com "Ask me about Database Illustrator(tm)" Ray Ontko & Co info_at_ontko.com ftp.ontko.com:/users/ontko (anon ftp) Received on Fri Aug 12 1994 - 15:33:47 CEST