Hi Markus, On 2011-08-24, at 1:49 AM, Markus Ruggiero wrote:
> Folks, > > I have the following requirement: I need a unique constraint on the > combination of 2 attributes. As I have learned from some postings about a > year back the distinct index in EOModeler does not work (and it surely does > not for me). Or should it? No, the indexing is not ready for use. > This is Oracle 9 and WO54, Eclipse Ganymed and suitable WOLips. So to at > least to ensure the integrity of the data I have defined a unique constraint > via SQL. But now I get a very ugli looking SQLException. This is functionally > ok but for the user not acceptable (understandable). > > How can I trap such an Exception during SAVE in a (ER)D2W app and present a > nice looking error message (similar to what is shown when some validations > fail)? > > Thanks a lot and have a nice day > ---markus--- It is tricky. The response from every database is different so you need some database specific code to interpret the exception. I think the best way is to use an EOEditingContext (ERXEC for Wonder apps) sub-class that catches the exception from saveChanges(), and interprets the exception. Done like that, it should be transparent to D2W. I have this implemented for some databases (Oracle is one of them!), in our GVC libraries but have not moved this to Wonder. I started a project in 2009 to complete this validation work and port to Wonder, but uh, er, it kind of fell off the top of my priority list. :-) The base, non-Wonder, code is here: http://sourceforge.net/projects/wovng/ You can get the "used in production" code from our Open Source frameworks: http://www.global-village.net/chill/gvc_frameworks The WOCommunity site has my presentation from WOWODC 2009: http://www.wocommunity.org/podcasts/wowodc/west09/WOWODCW09-Validation.mov Chuck -- Chuck Hill Senior Consultant / VP Development Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to [email protected]
