Re: User Defined Fields - HELP PLEASE!

I will take a contrary view. If the user wants user defined columns then perhaps he or she should have them.

There are applications on the market that are built to allow the user to define their own columns along with the vendor provided columns. One such product is MAXIMO, which is primarily an equipment maintenance planning and tracking system.

The customer can via the product add user columns. The columns can be updated, used in calculations, and reported upon.

It is just a matter of proper design to allow and handle extensions to the base design. Now adding user columns does bring with it the potential that the customer will then attempt to use the system in ways it was not designed to handle. That is a drawback and an argument against adding the user columns.

But the most important argument against adding the user columns in that your application was not designed to handle user columns to begin with.  To properly handle this functionality the application design has to include a dictionary that defines the user columns, have a means of allowing the customer to reference these columns, and to update these columns. That basically means the application needs its own reporting tool and screen generation tool. Or the columns are/were always part of the screen and just have null values until used. (Table driven screen labels).

But since your application was not designed from the start with these features adding user definable columns is not practical.

However, if what the customer really wants is to add a few additional columns that the original design did not consider then that is another issue rather than really being "user definable" columns. I would give the customer a fair hearing. You would probably want to start by providing him with a list of general rules for the columns that the customer is considering such as the need to relate to the PK of the tables in question, data type, and formatting.

PS - My mention of Maximo should not be taken as an endorcement. I strongly dislike several features of the product namely it requires a DBA priviled ID that allows the Maximo Administrator to define Oracle users, add indexes, and the application runs as the object owner.

HTH -- Mark D Powell -- Received on Tue Feb 22 2005 - 16:12:31 CET