Unhandled NilObjectException

Databases
1

Hi,
I am starting developing with xojo, and my 1st webapp works justfine when I debugg it in my local machine. Then after uploading it and when i try to access a mysql database, occurs an error:
This application has encountered an error and cannot continue.
[i]Unhandled NilObjectException
Message:

Stack:
WebPage1.WebPage1.ListarRegistos_Action%%o<WebPage1.WebPage1>o
Delegate.IM_Invoke%%o
AddHandler.Stub.28%%
WebButton._ExecuteEvent%b%osA1v
WebControl.!_ExecuteEvent%b%ssA1v
WebSession._HandleEvent%%oso<HTTPServer.HTTPRequestContext>
WebSession._HandleRequest%i4%oso<HTTPServer.HTTPRequestContext>
WebApplication.HandleHTTPRequest%%oo<HTTPServer.HTTPRequestContext>
_CGIGateway.GatewayRequestThread.Event_Run%%o<_CGIGateway.GatewayRequestThread>[/i]

I made a step by step test when I found that it was in this command code:

data = databasename.SQLSelect(sql)

2

maybe variable “databasename” is nil?

3

Hi
Thanks for the reply.
Localy on http://127.0.0.1/ works fine
The database is accessed from my local machine to a remote server as in the remote server.

4

maybe check your code?
Somewhere you open connection and that could fail.

5

So
why does it work localy?

6

USe the remote connection within the debugger and then stop the debugger at data = databasename.SQLSelect(sql) and check data, databasename and sql for NIL.

8

And you should add a If (databasename<>Nil, GoOnWithThat, StopDoingThis) somewhere. :slight_smile:

9

I would double check the mysql server on the remote machine is setup as you expect particularly with respect to the users. I just did what you a couple of weeks ago, and although I had everything setup correct on my home machine, when I moved it to a Linux VPS all did not play nice.

I knew it was how I setup MySQL. Took some messing around but was down to the user account I had setup & permissions.

As already mentioned make sure you perform checks for nil objects on the database as well.

10

Thanks everyone for the help.

The problem was:
Outside de the server has I granted % acess to the user there was no problem the web app works fine.
Inside the same server, the acess was blocked why?

  • The server name is not ‘localhost’

Solution:
grant full acess to the interal server name in the acesses host