Re: View updating in practice?

Daniel Morgan <dmorgan_at_exesolutions.com> writes:

> > 1. Do you use view updates? What is the scenario?
>
> Yes. Whenever I want to build a data block (for example in Developer
> Suite) containing information from multiple tables.

I don't know Developer Suite, but I suppose that you are talking about inserting something like an order, which is made up of a header with number, date customer id, and so on, and a number of line items, i.e., products actually ordered in the same order, into a join of two tables like Order and Lineitem. This makes sense from my point of view as the join is along a foreign key.

>
> 2. N/A
>
> 3. Use INSTEAD of triggers on a regular basis to implement appropriate
> support of the views.
>
> You do, in my opinion, make a number of invalid assumptions in your
> opening remarks. The biggest among them the fact that users have even
> the remotest clue of the design and structure of the underlying data.
> They don't know, they don't care, and likely they wouldn't understand it
> in without taking a class or two.

The question is the following: How dangerous are clueless users? If view updates are triggered from applications, then the application designer hopefully guarantees that the right things happen. If users access the database via SQL, they might delete valuable data.

>
> Software design is based on the concept of encapsulation. The ability to
> take complex functionality and present it in a clean, clear, and concise
> manner. If building a data entry form or report based on a view with
> instead of triggers serves that purpose ... then it is (assuming no
> problems with performance and scalability) the optimal solution.

I have no objections to that.

>
> And, while I understand you are involved in theoretical studies,
> and are likely deeply into academia, understand that end user's,
> and most developers, would know a tuple if it sat down with them
> for dinner.

As I said above (and unfortunately did not make clear in my original posting): I'm concerned about users (or developers) with SQL access. I hope that they know tuples...

Thanks for your feedback,

Jens Received on Fri Nov 08 2002 - 18:09:30 CET