ORA-20104: create_collection_from_query ParseErr:ORA-00918: column ambiguously defined

Always check out the original article at http://www.oraclequirks.com for latest comments, fixes and updates.   If you are wondering why you are getting this error message after following the example in the documentation describing procedure CREATE_COLLECTION_FROM_QUERYB2 in the APEX_COLLECTION API, the quick answer is that the sample code is flawed. ORA-20104: create_collection_from_queryb2

Apex substitution strings in reports, not always replaced with their values, guess why?

Always check out the original article at http://www.oraclequirks.com for latest comments, fixes and updates. It's amazing to you find out how easy is to take for granted certain features of Apex for the simple fact that you have been using them for a long time without paying too much attention to certain specific details. This morning I ran a report that I rarely use in an application and to

How many page views can Apex sustain when running on Oracle XE?

Always check out the original article at http://www.oraclequirks.com for latest comments, fixes and updates. While some people think that hosting a web site on top of Oracle XE can be hardly considered much more than a joke, I can claim instead, basing on my personal experience of the last 5 years, that for small sites it can be a perfectly reasonable choice, provided you have the technical

Submit from jQuery modal causing session state protection violation

Don’t you hate those nagging issues where you attempt a few fixes in vain, waste hours of your life, and then suddenly the issue just resolves itself? What’s worse than an issue that won’t go away is one that just resolves itself and you don’t know why. You don’t know if it is just hiding, waiting to reappear at some inconvenient time later (e.g. when the app goes live in Production).

I added the (more...)

Change the Apex parsing schema at runtime

One of our clients needed an application for the follow-up of the production in their plants. The main feature of the application was to show all the data of the current year, but the client also wanted to be able to consult the historical data. Unfortunately the historical data was not in the same schema as the current data.

The two schemas:

  • SCHEMA_A
  • SCHEMA_A_HISTORY

As you could already guess, the second schema contained the historical data. Each year, (more...)

Time for an Oracle Apex feature request – single sign-on authentication

I've just submitted a feature request because I believe that the current Application Group concept is a fairly weak one if it doesn't bring about some advantage in terms of features for the developer. Basically what I am asking for is that one can easily implement a single sign-on authentication method across multiple applications within the same application group, pretty much like the existing

I am running for the ODTUG Board of Directors

After some thought, I decided I will be running for the ODTUG Board of Directors this year. I have been attending Kscope since 2008 (New Orleans). Presented at Kscope and APEXPosed since 2009. Did a few webinars. Was a member of the APEX Content Team for Kscope12 and 13. And now I am the Content Lead for the APEX track for KScope14 and Kscope15. So I like spending my free time for ODTUG, to keep (more...)

"Busy Button" with APEX5, jQuery and Font Awesome

Both jQuery and Font Awesome are standard included with APEX5 (still in early adopter). With a little bit of jQuery you can create an animated button that reflects that it is doing something in the background.
For this example I created a button "Text + Icon button". Simply drag and drop this in the Page Designer.
The Icon CSS Class: "fa-play-circle-o"
and the action: "Defined by Dynamic Action"
For the Dynamic Action: it should respond (more...)

Dynamic Action in Report – APEX5 version with Font Awesome

Almost two years ago, I wrote a little blog on how to trigger a Dynamic Action from a report. You can find that blog right here.
Things have changed with APEX5 (which is currently still in "early adaptor 2") which allow you to do this in a more clean way (or at least I think so). No need to create a "fake link" so the user know that the icon is clickable. No need to (more...)

Show an animated “Please wait” indicator after page submit

My application normally responds to button clicks with sub-second performance, but there were a few operations where users can initiate quite long-running transactions (e.g. up to 15 seconds long in one case where it was hitting an eBus interface thousands of times).

When the user clicks the button, I want the page to show a “Please Wait” message with an animated running indicator (I won’t call it a “progress bar” even though it looks (more...)

Multirecord Master-Detail Report

A common requirement is to show a Master-Detail Report where both the Master as well as the Detail Report show multiple records. When you click on one of the Master records, the connected detail records are shown as well.
This is very easy to accomplish with a Hidden item and a Dynamic Action.
First the Master Report, for this example I am using the DEPT table:

select d.deptno
,d.dname
,d.loc
from dept (more...)

Add a Dynamic Total to a Tabular Report

I have a Tabular Report with an editable Amount item. When the page loads, the total amount should be shown below the report; and if the user updates any amount on any row, the total amount should be updated automatically.

Note: this method does not work if you have a tabular report that might have a very large number of records (as it relies on all records being rendered in the page at one time).

(more...)

Show/Hide Multi-row Delete button for a Tabular Report

I have a standard tabular report with checkboxes on each row, and a multi-record delete button called MULTI_ROW_DELETE.

If the user clicks the button before selecting any records (or if there are no records), they get an error message. Instead, I’d rather hide the button and only show it when they have selected one or more records.

showhidemultirowdelete

To do this:

1. Edit the MULTI_ROW_DELETE button to have a Static ID (e.g. “MULTI_ROW_DELETE”).

2. Add (more...)

Using Post-Authentication to run process after APEX login

A frequent requirement, and hence frequent question on the forums is
How do I run procedure x after the user has logged in?
This is often required for such tasks as determining user access, such as populating a restricted Application Item relating to a role like F_IS_ADMIN based on the username defined in substitition string APP_USER

Those new to APEX and unfamiliar with certain concepts may consider using an Application Computation, firing "On New Instance (more...)

The curious problem of Apex login page session expiration

Always check out the original article at http://www.oraclequirks.com for latest comments, fixes and updates. Did you ever notice that if you open an Apex page requiring authentication but you don't log in during a long time, it may happen that when you finally try, you are bounced back? That happens because even the Apex login page obeys the session expiration rules defined either at the

Autoformat ANY amount item, anywhere

If you’re building a “finance-ey” application you probably have plenty of fields that should show and accept monetary amounts – and quite possibly these items may be implemented in a variety of ways – ordinary apex number items, edit fields in tabular reports, or even dynamically generated items using APEX_ITEM.text.

In my case I had all three, scattered throughout the application. Our users routinely deal with multi-million dollar amounts and they had trouble checking the amounts visually, (more...)

UKOUG Tech 14 in Liverpool

I’ll be going to the UKOUG Tech 14 conference in Liverpool in December to give one of my favorite presentations: “APEX or ADF? From Requirements to Tool Choice”. I’m also leading the Development Tools roundtable, which is always lively at the UKOUG conference. If you want to discuss your options as a developer in the Oracle world, UKOUG Tech 14 is the place to be.

APEX or ADF? From Requirements to Tool Choice
APEX or (more...)

APEX: Save a user’s checkbox selection on local PC

You want a checkbox item on a page which is a preference, you want it to be remembered for the user across login sessions, but you don’t want the overhead of storing it in a database table. You might choose to store the value in a cookie instead. It may be lost (e.g. when the user clears their cookies or changes to a different browser or another computer), but we don’t mind – it’s just a preference.

stayonpage

(more...)

Glorious mysteries of Oracle’s web site

God or Larry knows why Oracle feels the compelling need of changing some of its page links over time. Oracle Application Express' main page URL is now: http://www.oracle.com/technetwork/developer-tools/apex/index.html It was: http://www.oracle.com/technology/products/database/application_express/index.html May be I am a bit slow in picking up these changes, I don't really know if this

APEX 5: Using Font Awesome Icons in Report

APEX 5 is currently in Early Adaptor 2, so the exact implementation of this blogpost might change when APEX 5 goes GA.
Font Awesome is standard included with APEX 5 and you can use the icons on buttons, there is a special property for that.
I was playing around the other day and I wanted to include some Font Awesome icons in my report.
First create a report (classic or interactive, whatever you want) and (more...)