Skip to main content

A Better Method

Just posted a new Tip over on sumneva.com that deals with quickly creating a package that can manage all DML transactions against a table or tables.

I came across this feature in the days of APEX 4.0 EA1.  I immediately thought that it was a new APEX 4.0 feature - until I checked 3.2, and it was there too.  Basically, this allows you to easily create a table API which can be used to replace the built-in APEX DML processes.

Why would you do this?

If you wanted to create a more secure architecture, you may want to have a tableless schema - thus, the built in processes will do you little good.  This API can live in a separate schema, and facilitate all DML calls used to manage your data.

Since it's in a PL/SQL package, you can easily add additional security or data integrity checks before performing any of the DML transactions - another major reason to consider this approach.

Comments

Patrick Barel said…
Maybe you could check out the QDA (Quest Development Architecture) available in QCGU (Quest CodeGen Utility) at http://codegen.inside.quest.com/index.jspa
Anonymous said…
Also someone did a long time ago but never...
http://www.danielmcghan.us/2008/07/tapigen-demo-app.html
Anonymous said…
also forgot his source code website too..
http://sourceforge.net/projects/tapigen/
Thanks for the tip Scott I have had questions from people on this type of setup for some time, and no really good answers. Now this one bears a little experimentation. :")
Scott said…
I do remember now that this feature was built WITH Dan's TapiGen APIs. Dan - if you're watching - can you confirm?

- Scott -
Joel R. Kallman said…
>> I do remember now that this feature was built WITH Dan's TapiGen APIs. Dan - if you're watching - can you confirm?

Really? That's odd. The date on Dan's code is 2008, the APEX TABLE API generator was written in February 2003. And the code between them is completely dissimilar. Dan's is way more sophisticated.

Sorry, but I don't think that statement is accurate at all.
Scott said…
I stand corrected.

Thanks, Joel.

- Scott -
Ino said…
Scott

I saw your ODTUG webcast about this subject, and tried it out myself. I think that this API is really too simple to use. E.g. for an update it doesn't take into account the columns you actually want to change, so the others may turn up as NULL after the update.

Also, the API cannot (easily) be used in a tabular form.

One of the suggestions in the webinar was to use views with instead of triggers. That could be a better solution.

Ino
Scott said…
Ino,

If you pass all parameters back to the API, then they should all be updated. If you NULL some of all of them out, well, then your data will also reflect that.

Keep in mind that the example that I used is just one example; you could likely build an API generator that is more robust and suits your specific needs in no time at all.

I am not a huge fan of Instead of Triggers, as there is no way to rollback anything, should something fail. For example: how would you handle lost update detection?

Thanks,

- Scott -

Popular posts from this blog

Custom Export to CSV

It's been a while since I've updated my blog. I've been quite busy lately, and just have not had the time that I used to. We're expecting our 1st child in just a few short weeks now, so most of my free time has been spent learning Lamaze breathing, making the weekly run to Babies R Us, and relocating my office from the larger room upstairs to the smaller one downstairs - which I do happen to like MUCH more than I had anticipated. I have everything I need within a short walk - a bathroom, beer fridge, and 52" HD TV. I only need to go upstairs to eat and sleep now, but alas, this will all change soon... Recently, I was asked if you could change the way Export to CSV in ApEx works. The short answer is, of course, no. But it's not too difficult to "roll your own" CSV export procedure. Why would you want to do this? Well, the customer's requirement was to manipulate some data when the Export link was clicked, and then export it to CSV in a forma

Refreshing PL/SQL Regions in APEX

If you've been using APEX long enough, you've probably used a PL/SQL Region to render some sort of HTML that the APEX built-in components simply can't handle. Perhaps a complex chart or region that has a lot of custom content and/or layout. While best practices may be to use an APEX component, or if not, build a plugin, we all know that sometimes reality doesn't give us that kind of time or flexibility. While the PL/SQL Region is quite powerful, it still lacks a key feature: the ability to be refreshed by a Dynamic Action. This is true even in APEX 5. Fortunately, there's a simple workaround that only requires a small change to your code: change your procedure to a function and call it from a Classic Report region. In changing your procedure to a function, you'll likely only need to make one type of change: converting and htp.prn calls to instead populate and return a variable at the end of the function. Most, if not all of the rest of the code can rem

Logging APEX Report Downloads

A customer recently asked how APEX could track who clicked “download” from an Interactive Grid.  After some quick searching of the logs, I realized that APEX simply does not record this type of activity, aside from a simple page view type of “AJAX” entry.  This was not specific enough, and of course, led to the next question - can we prevent users from downloading data from a grid entirely? I knew that any Javascript-based solution would fall short of their security requirements, since it is trivial to reconstruct the URL pattern required to initiate a download, even if the Javascript had removed the option from the menu.  Thus, I had to consider a PL/SQL-based approach - one that could not be bypassed by a malicious end user. To solve this problem, I turned to APEX’s Initialization PL/SQL Code parameter.  Any PL/SQL code entered in this region will be executed before any other APEX-related process.  Thus, it is literally the first place that a developer can interact with an APEX p