Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
Using a Database or Free Standing Tables?
Message
General information
Forum:
Visual FoxPro
Category:
Other
Miscellaneous
Thread ID:
00194522
Message ID:
00195276
Views:
27
>
>Let me address some of the "disadvantages" that have been quoted.
>
>1) Handling errors: The trigger and field rules create an error conditon when they fail, it is easy to write an error handler that can handle those errors. The features exist in the language to find out what error occured and where it occured.
I wasn't aware that all such errors could be trapped.
>
>2) The rules cannot be suspended: If the rules need to be suspended then they aren't rules in the first place. Database schema rules are absolute. Business rules change over time. One should not use a databse to enforce business rules.

Agreed. But what is a business rule vs. a RI rule. One client may say that he needs to have a customer for every invoice that is entered and another may say that they need to be able to enter an invoice and associate it with a client later(idea from 'About Face').
>
>3) What if I need the same rules in another app?

What if you want to use a different front end to access your VFP data? If you don't use a database then you have no way of insuring that the rules are enforced. You have to depend on the developer of the other app to enforce the rules properly in their app.

The idea is to force all access to data to go through enterprise level business objects (could be hosted on MTS). Rules are centrally enforced, in particular the application developer cannot break the rules unless they are allowed direct access to the data. Just like a database server does not allow direct access to the data, developers would not be allowed direct access to the data.

>
>Why does it seem that free tables are easier? Because the free tables have extremely more limited capabilities, which translates to your needing to know and understadn considerably less in order to exploit their features. Databases have a lot more capablility, whihc emans that to use that capability to its full function and to create effective databses, you must leanr the abilities and the nuances of the database and its features. But, remember, you only need to learn it once, then you can use the features over and over again.
Not easier, less restrictive.

Ned
Ned

Reality is.
Previous
Next
Reply
Map
View

Click here to load this message in the networking platform