Oracle application - appcrash

Hi all,

I’m writing an application which connects to an Oracle DB.
Connection with the DB is fine.
However, when displaying information from recordsets in the UI , it crashes a lot.
Sometimes when I add …stringvalue.DefineEncoding(Encodings.UTF8) it fixes the problem, in some cases i have to remove the define encoding to fix it.

The crashes look like this:
Problem signature:
Problem Event Name: APPCRASH
Application Name: DebugApp Desktop.exe
Application Version: 1.0.0.0
Application Timestamp: 53da569a
Fault Module Name: MSVCR120.dll
Fault Module Version: 12.0.21005.1
Fault Module Timestamp: 524f7ce6
Exception Code: c0000005
Exception Offset: 0000ee2c
OS Version: 6.1.7601.2.1.0.256.48
Locale ID: 2067
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

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Adding some code to display more information crashes the app more and more. I don’t seem to be able to figure out why it crashes. It seems to be related to UTF8 encoding, but I am not sure. Remove or adding the encoding fixes or breaks the code with no apparent pattern.

Any suggestions? Do I need to set the encoding in the connection like with MySQL (SET NAMES ‘UTF8’)?

Any help would be really appreciated because my app is really not usable. It crashes most of the time fetching and displaying information.

Thanks for any help.

Michael

I always hesitate when answering forum questions because I feel like a beginner myself.

This may be a dumb question but are you sure the field in the recordset contains data to be displayed?

I had trouble with a Windows Service that queries Oracle because Oracle would return NULL in a field and crash the service. Checking for NIL per field solved it for me.

i.e. If TheRecordSet.Field(“TheField”)<>Nil Then…

MSSQL and Postgre by contrast will return a recordset field with nothing in it if the Field is NULL.

Shouldn’t the application throw a NilObjectException when a field is Nil and is being used instead of a hard crash (Appcrash)? Anyway, I’ll give your suggestion a try.
The weird thing is that the appcrashes seem to be random also very often. For instance, compiling my app a few times doing the exact same sequence of actions most of the times causes an appcrash , sometimes it doesn’t. Could it be that the Oracle DB Plugin in Xojo is very unstable? I’m using Xojo 2014 r2.1

I agree. It should throw the nilObjectException but it crashed the app instead (a service app in my case) until I started checking for NIL. It may have the same symptom in a GUI (desktop) app as well. We should probably file a feedback case if it turns out to be the same issue for you.

I know it looked random to me while I was dealing with it. The weird thing for me was that it would sometimes get all the way through without a crash.

I also remember asking the Oracle DBA about what encoding they were using but all of the code that deals with encoding is remarked out. I do have every field that may present a NULL wrapped in an a check for NIL.

This is the only thing I have accessing Oracle and it only pulls data from three views created for me but my gut feeling is that it’s pretty stable. My service has been running smoothly for about 5 years now.

I have recently re-compiled the service with Xojo 2014r1 due to some changes I had to make. The new compile is also running smoothly.

Hi all,

Now with the latest version I am still experiencing random crashes. Sometimes it works for minutes.
Sometimes seconds after starting the application it crashes with these errors:

Problem signature:
Problem Event Name: APPCRASH
Application Name: DebugSalduz Desktop.exe
Application Version: 1.0.0.0
Application Timestamp: 54b4134a
Fault Module Name: RBGUIFrameworkWin32.dll
Fault Module Version: 14.3.3.1
Fault Module Timestamp: 54b416c2
Exception Code: c0000005
Exception Offset: 0003d499
OS Version: 6.1.7601.2.1.0.256.48
Locale ID: 2067
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

Read our privacy statement online:
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Any suggestions?
My application is unusable at the moment if it keeps crashing like that.
It seems to be related to querying the oracle database and filling in list boxes with the content from the database.