Re: foreign key rule error

"victorrhee" <member_at_dbforums.com> wrote in message news:1958214.1035301651_at_dbforums.com...
>
> Thanks Daniel and Vitaliy
>
> Daniel, I appreciate your comments and must admit I'm very confused. My
> earlier attempts to research the problem took me to C J Date's textbook
> "An Introduction to Database Systems" (25th Ed.) where I followed the
> example on page 269. This also confirmed my class notes, however the
> code wouldn't process. I did finally get the table created by only
> including one 'referential action' (in this case "on delete cascade") in
> each foreign key statement.
>
> I'm 3 months into my Information Systems subject and the terms "PCTFREE,
> PCTUSED, INITIAL, NEXT" are not known to me. Daniel, I would be grateful
> if you could recommend reference material that expands on your comments
> about creating tables.

Your problem is ,fundamentally, that you are assuming that RDBMS vendors provide implementations of the relational model and the sql language which match the textbook (or ANSI standard) descriptions. They don't. As you found 'ON UPDATE CASCADE' has to be coded for yourself in oracle. similarly the terms which Daniel uses, and with which you are unfamiliar, are storage parameters for database objects, and are Oracle specific.

I'd definitely take up Sybrand's suggestion and study the docs at tahiti.oracle.com (start with the concepts manual) in conjunction with your (university?) course. You might find it worthwhile to run at least one or two of your projects an another RDBMS to get a feel for implementation differences once you are familiar with the concepts and one particular implementation.

--
Niall Litchfield
Oracle DBA
Audit Commission UK
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