Updating detail columns

Question

Guys,
I am really really new to Apex (first day)
I am playing around with the master detail form (which I will be using a lot). and I could not able to find a way to add validation / conditions to the columns in detail table. (I have setup my form so that user can modify the columns on the maserdetail page itself they don't need to open another page to add / edit any informatin)
Let me know any way to add validation (post / pre) to columns defined in detail table
thanks....
-R
Edited by: user12236377 on Jan 29, 2010 12:55 PM

Answer 1

Hi R,
Since ApEx applications are simply dynamic HTML applications driven by an Oracle database, you're free to take advantage of javascript to validate at the browser as well as PL/SQL to validate at the server. (Note that PL/SQL validations are server-side validations - not browser-side validations.)
That said, with all of the flexibility and robustness (if that's a word) that ApEx (and Oracle) provides concerning validations, I don't believe I've ever written a javascript validation for an ApEx application. Why?
1) Javascript can be turned off at the browser, essentially disabling all your validations. (This is something all web-application developers have to contend with - not just ApEx)
2) Because of #1, you end up having to duplicate your validations at the server to protect against corruption. Read: maintenance nightmare.
In my opinion, all a javascript validation buys you is not having to round-trip to the server. But then what I so often see is all these alert messages popping up that this is wrong, that's wrong etc. every time I tab out of a field - annoying. To me, with slow-dialup fading away and servers getting more and more powerful, I don't care about an extra round-trip or two. I'd rather submit a page and see all the error messages displaying nicely next to the fields like ApEx does for me - and once I use the application a couple times, I'll learn what it's looking for and the round-trips will go down to almost nothing.
Then I only need one set of validations on the database keeping my data nice and clean and, if I did a good job designing for re-use, I'll be able to take advantage of those exact same validation routines for alternate means of input like say, web services!
Hope this helps,
John