Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Intercepting SQL Server connection errors in Access VBA code, over a VPN

Posted on 2014-03-06
6
Medium Priority
?
1,092 Views
Last Modified: 2014-06-26
I have an Access application that is running on the computers of numerous individuals at one of my clients, running various different versions of Windows and Office.  We have migrated a number of tables to SQL Server but the connection strings for the different computer configurations are different, so I have a function which attempts to open a pass-thru query that selects the first record from one of the tables on the SQL server.  If that process raises an error, the error handler attempts several other connection strings until it finds the proper one for the current users computer; that part works fine.

However, some of the users of the application do so over a VPN, with the application on their home or laptop and if they have failed to open the VPN connection prior to running the application, the receive the following error message:
Connection Failed:
SQLState: '01000'
SQL Server Error: 53
[Microsoft][ODBC SQL Server Driver][DBNETLIB][ConnectionOpen(Connect()).
Connection Failed:
SQLState: '08001'
SQL Server Error: 17
[Microsoft][ODBC SQL Server Driver][DBNETLIB]SQL Server does not
exist or access is denied.

Open in new window

which is not intercepted by the Access error handler.  How can I intercept that error and handle it cleanly within my application?  Or is their some easy to test whether the VPN connection is open?
0
Comment
Question by:Dale Fye
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 43

Expert Comment

by:Eugene Z
ID: 39911464
here you are:

Potential causes of the "SQL Server does not exist or access denied" error message
http://support.microsoft.com/kb/328306

looks like you are using DSN ODBC that may need to be checked with potential adjustment of uid\pwd sql server name there and verification of the sql uid\pwd sql server name  by attempt to login on sql server via ssms to make sure that "sql server exists and used sql login has access to sql server\DB there"
0
 
LVL 16

Expert Comment

by:DcpKing
ID: 39911537
Take one of the machines home with you and set it up on your home network. You'll get an IP something like 192.168.0.4 or 192.168.1.5. There's a list available of class C addresses that can be used by anyone because they're kept behind a NAT and not seen by the outside world - hence lots of people have the same IP addess but don't collide.

Anyhow, then open up the VPN and everything and get into your work network. At this point you'll be on another network and you'll probably have a different address range - 10.something, in all likelihood.

Anyhow, have a server in work that Access can try to find: if it does then it's operating via the VPN, and if not it can tell the user to open up the connection.

hth

Mike
0
 
LVL 58

Assisted Solution

by:Jim Dettman (Microsoft MVP/ EE MVE)
Jim Dettman (Microsoft MVP/ EE MVE) earned 800 total points
ID: 39912233
I think I would simply take the server name from the connect string and try to ping it.  That will tell you if the network is up or not.

Jim.
0
Use Case: Protecting a Hybrid Cloud Infrastructure

Microsoft Azure is rapidly becoming the norm in dynamic IT environments. This document describes the challenges that organizations face when protecting data in a hybrid cloud IT environment and presents a use case to demonstrate how Acronis Backup protects all data.

 
LVL 24

Accepted Solution

by:
Bitsqueezer earned 1200 total points
ID: 39915519
Hi,

in all connection strings always use the FQDN (full qualified domain name) and not only the name of the server. As an alternative you can also use the IP address but it's better to use the FQDN as an IP address could change sometimes (not very often in case of servers).

Sometimes a big network is divided into several subnets and without the FQDN it only searches in the direct reachable subnet and not all the others (depending on your network configuration).

Cheers,

Christian
0
 
LVL 48

Author Comment

by:Dale Fye
ID: 39957685
Have not been able to pursue this as I've been working several other short suspense tasks.  Hope to get back to this soon.
0
 
LVL 48

Author Closing Comment

by:Dale Fye
ID: 40161420
Thanks guys.  Finally got back to this decided to use Christian's method but liked Jim's approach as well.
0

Featured Post

Survive A High-Traffic Event with Percona

Your application or website rely on your database to deliver information about products and services to your customers. You can’t afford to have your database lose performance, lose availability or become unresponsive – even for just a few minutes.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In the first part of this tutorial we will cover the prerequisites for installing SQL Server vNext on Linux.
Traditionally, the method to display pictures in Access forms and reports is to first download them from URLs to a folder, record the path in a table and then let the form or report pull the pictures from that folder. But why not let Windows retr…
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.
Do you want to know how to make a graph with Microsoft Access? First, create a query with the data for the chart. Then make a blank form and add a chart control. This video also shows how to change what data is displayed on the graph as well as form…

705 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question