Physical Database Layer Change and Business View Layer

[gosoccer]

Hi Experts, :) :)

I'm hearing that there is a way to keep the Business Layer Subject Queries constant even if the Physical Layer Database Table
changes. I have three namespaces. Physical View, Business View, and Presentation View.

Now, I have build the Business View Subject Queries from the Physical View Subject Queries (Direct SQL). Of course Physical View Subject Queries are build directly from the Source database.

The report is actually using the Business View layer and not the Presentation Layer since I thought I use the Presentation Layer for
other purposes.

So, if there is a DB Column or Table change, how would the Business View layer help?

Thx so much for your time.

[cognostechie]

May I know what is the 'other' purpose you want to use the Presentation layer for?

If you do not have access to any training courses then it is a good idea to read the user guide which comes with the software. That way,
you will understand how the tool is architected, how should it be used and what value is it designed to provide.
You have been posting questions on the FM forum for quite some time now and you are not familiar with the very basics ? In the Business Layer,
the query subjects should be 'Model' query subjects , not the Database Query subjects which you should have only in the Database layer.
Model QS can be re-pointed to the changes columns of the Database Query subjects of the Physical Layer so there will be no impact to the reports
(presuming the changes in the database are limited to some extent which will make it possible to keep the Business layer intact).

[gosoccer]

That's what I have:
"In the Business Layer,
the query subjects should be 'Model' query subjects , not the Database Query subjects which you should have only in the Database layer."
My Physical Layer is the only Layer pointing to the DB through the datasource."

I was trying to findout when a Table or Column change occurs such as Table/Column Name, how does that impact the  business layer.

I'll check it myself!!!

[cognostechie]

May I know what is the 'other' purpose you want to use the Presentation layer for?

If you do not have access to any training courses then it is a good idea to read the user guide which comes with the software. That way,
you will understand how the tool is architected, how should it be used and what value is it designed to provide.
You have been posting questions on the FM forum for quite some time now and you are not familiar with the very basics ? In the Business Layer,
the query subjects should be 'Model' query subjects , not the Database Query subjects which you should have only in the Database layer.
Model QS can be re-pointed to the changes columns of the Database Query subjects of the Physical Layer so there will be no impact to the reports
(presuming the changes in the database are limited to some extent which will make it possible to keep the Business layer intact).

When you actually create a Model Query subject then you will know how it is different than the Database query subject and then you will instantly know how to re-point it to the changes of the physical layer.

[gosoccer]

Ok, I'll search for Creating Model Query to see if it's any different than what I have done already by building the Subject Query from a
Physical Data Layer Subject Query using the Model option and not Datasource. Thx in advance for your time.

[bdbits]

The business layer is not normally something you expose to users. That's what the "presentation" layer is for - presenting to users.

[gosoccer]

Well, I was hoping to use the Presentation Layer for the Ad-HOC Query capability using Workspace Advanced. So, in this case, the column names
will actually change to be more user friendly as a part of Framework Model Presentation Layer Subect Queries. If you have any suggstions, please let me know.

Thx so much in advance for your time. :) :)

[bdbits]

You can make multiple presentation layers, even put them in separate packages if you want. I just do not want to expose the business layer as you have done. I know personally I sometimes have stuff in a business layer that I would not necessarily want to let users access, lest they create something that creates a dependency that would break if I make a change in that layer. And I organize it somewhat differently than the presentation layer, as well.

So the short answer to your original question is to make multiple presentation layers. Since you have already exposed the business layer, you might consider refactoring the exposed layer into a presentation layer built on a new non-visible business/query layer. Could be a bit of work, but you are probably better off in the long run if you make that investment now.

[gosoccer]

Thank you. I'm going to back to use the Presentation Layer by performing some extra work on my own time. I'm not as experienced as I should be and time is so limited but I think your suggestions is very important. So, the quick question is how to build the Presentation Layer.

Would it be continue after the Namespace Creation, make short cuts and drag the Shortcuts of the Subject Queries to Presentation Layer OR go through the following step:

Right Click on the Presentation View
Create-Query Subject
Name the New Query Subject
Select the option Model (NOT DATASOURCE)
Save the New Query Subject under Presentation View.

Thank you again for all your time. I'm just runing some ideas to see which method is best.

[bdbits]

If the presentation layer query subject is one-to-one with a business layer query subject, I have no problem with shortcuts. And actually, that is what I often have in my own models. The annoying thing is then removing the "Shortcut to" they tack on the front. :)

[gosoccer]

OK, Super! Thanks for verifying some of my understanding. I greatly greatly appreciate your time. 8)