Skip to main content

First impressions of Washington...

On Saturday I had a very well scheduled travel from my home to Washington. Even the plane departed and arrived exactly as scheduled. And while the line for the US Border Security was quite long, it only took half an hour or so to take that hurdle. I have seen worse (1,5 hour in Houston), but also better (5 minutes in Minneapolis).
In my shared shuttle drive to the hotel the impression I didn't get an impressive view of Washington: just the regular broad streets packed with stores and restaurants. Once out of the shuttle the impression is that it is impressively hot and humid. Not as bad as New Orleans, but still.
After registration I went for a Indian dinner with Monty and Mark, I even managed to stay up until 10PM (and that with a 6 hour time difference). Due to that time difference I first woke up at 4AM, but managed to stay sort of sleeping until 6AM. Still to early for breakfast, but that gives me the chance to write this short blog post.
Today there are two important things on the agenda: The England vs. Germany game, and the APEX Cookbook symposium. But I'll might join them later, cause I think I'll pay a visit to the zoo first - while it is not that hot.

Comments

Popular posts from this blog

Filtering in the APEX Interactive Grid

Remember Oracle Forms? One of the nice features of Forms was the use of GLOBAL items. More or less comparable to Application Items in APEX. These GLOBALS where often used to pre-query data. For example you queried Employee 200 in Form A, then opened Form B and on opening that Form the Employee field is filled with that (GLOBAL) value of 200 and the query was executed. So without additional keys strokes or entering data, when switching to another Form a user would immediately see the data in the same context. And they loved that. In APEX you can create a similar experience using Application Items (or an Item on the Global Page) for Classic Reports (by setting a Default Value to a Search Item) and Interactive Reports (using the  APEX_IR.ADD_FILTER  procedure). But what about the Interactive Grid? There is no APEX_IG package ... so the first thing we have to figure out is how can we set a filter programmatically? Start with creating an Interactive Grid based upon the good old Employ

apex_application.g_f0x array processing in Oracle 12

If you created your own "updatable reports" or your custom version of tabular forms in Oracle Application Express, you'll end up with a query that looks similar to this one: then you disable the " Escape special characters " property and the result is an updatable multirecord form. That was easy, right? But now we need to process the changes in the Ename column when the form is submitted, but only if the checkbox is checked. All the columns are submitted as separated arrays, named apex_application.g_f0x - where the "x" is the value of the "p_idx" parameter you specified in the apex_item calls. So we have apex_application.g_f01, g_f02 and g_f03. But then you discover APEX has the oddity that the "checkbox" array only contains values for the checked rows. Thus if you just check "Jones", the length of g_f02 is 1 and it contains only the empno of Jones - while the other two arrays will contain all (14) rows. So for

Stop using validations for checking constraints !

 If you run your APEX application - like a Form based on the EMP table - and test if you can change the value of Department to something else then the standard values of 10, 20, 30 or 40, you'll get a nice error message like this: But it isn't really nice, is it? So what do a lot of developers do? They create a validation (just) in order to show a nicer, better worded, error message like "This is not a valid department".  And what you then just did is writing code twice : Once in the database as a (foreign key) check constraint and once as a sql statement in your validation. And we all know : writing code twice is usually not a good idea - and executing the same query twice is not enhancing your performance! So how can we transform that ugly error message into something nice? By combining two APEX features: the Error Handling Function and the Text Messages! Start with copying the example of an Error Handling Function from the APEX documentation. Create this function