Communication Link Failure

[SteveDingle]

Heya All,

While this does have to do with ODBC, I thought I would post here in case anyone has any specific VFP experience with this error, I have scoured the web and not found anything helpful.

Basically client is running and app of mine which is talk updating a SQL Server 2K database. Randomly they will start getting the ODBC Communications Link Failure back.

Problem is that it only seems to happen with MY VFP app :-( While they are getting that error form my app, they can connect to the database no problems via other applications and means

Of course the problems are compound in 1) I can't duplicate it here b) they are in USA and I'm in UK

Any thoughts would be helpful


Toodles,
Steve Dingle

http://www.dsbusinesssolutions.co.uk

D&S Business Solutions Ltd

 

[Neil Toulouse]

I dare say you have come across this as there is very little on the web about it:

" Make sure that your largest column is the last column retuned. Make sure that you do not have any columns returned after a text or an image column "

No idea what platform it is refering to though, or how you can test it properly if you can't replicate the error!

Neil

I like work. It fascinates me. I can sit and look at it for hours...

 

[JRB-Bldr]

When you say..
"While they are getting that error form my app, they can connect to the database no problems via other applications and means"

Are the 'other applications' also communicating via ODBC?
And, if so, are they all using the same DSN?

I have seen some DSN definitions where the IP address is specified and others where the server 'name' is specified and, associated with that, situations where one DSN worked and the other did not.

Are you familiar with Windows UDL files?

http://aspalliance.com/434_Database_Access_Using_UDL_Files.2

These are little files which can be used to independently (independent from the application) to test the ability of a DSN to connect via ODBC to the back-end.

When I have trouble with ODBC connections I use the UDL file as a first step in troubleshooting the problem. Find which DSN's work and which do not and then look into the difference.

With the situation where one DSN works and another one does not and the difference is how the back-end server is specified, I merely change the bad one. I have been told (and not had time to confirm it) that in these instances the problem is in the Windows Server DNS (what an alphabet soup DSN-DNS, oh well).

For fixes to individual workstations, I have typically resolved the DSN IP/Name issue with an entry into the Hosts file in the C:\WINNT\system32\drivers\etc directory.

Good Luck,
JRB-Bldr