Question

I already asked this question before, but without any good response,
my problem is that I have a local database (aspnetdb.mdf) in my app_data folder, here is the connection string in the web.config :

<add name="ApplicationServices" 
     connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true" 
     providerName="System.Data.SqlClient" />

so my site works fine in my local iis server, but when i put the site in my host server, I get this error message :
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified).

In the other server I have sql server 2008 (the remote connection is accepted and i have the same instance name SQLEXPRESS). I really tried everything that I can but without any good results. I will really appreciate your help, thx.

Answer 1

This format indicates a local connection:

.\SQLEXPRESS

From another server, you’ll need to specify a server name or IP address, e.g.:

192.168.1.205\SQLEXPRESS
YOURMACHINE\SQLEXPRESS

You’ll also need to validate that the instance is SQL Server Express. From your other nearly identical question it looks like a default instance.

You should also stop using this silly user instance / attachDbFilename technique. Attach your database to the instance properly, then reference the logical database name using Initial Catalog=aspnetdb; in your connection string. This user instance feature was deprecated for multiple reasons, and this is certainly one of them.

Of course there may be other network issues that will prevent this, e.g. if the server is in a different domain, there are firewall settings interfering, etc. But your other server is never going to be able to access your machine using a dot for the server name.

EDIT providing baby steps because obviously my advice is not being followed. Assuming you have actually attached the aspnetdb database on the new server, try this please:

 connectionString="data source=192.168.85.124\SQLEXPRESS;
   Integrated Security=SSPI;
   Initial Catalog=aspnetdb;" 

If you aren’t using SQL Express named instance after all, try:

 connectionString="data source=192.168.85.124;
   Integrated Security=SSPI;
   Initial Catalog=aspnetdb;" 

For SQL authentication use the same username/password you use in Management Studio:

 connectionString="data source=192.168.85.124;
   User ID=username; Password=password;
   Initial Catalog=aspnetdb;" 

This is troubleshooting 101 stuff. If you still can’t get this to work, you may have to hire a consultant for 10 minutes to fix it for you since it’s impossible to figure out what you’ve done and why you can’t get it to work.