C# – A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found,etc

cconnection-stringpublishvisual studio 2010

I'm just publishing my website to my domain name and when I try to access it in my browser I get the Following error:

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)

I think the problem is into my connection String ==>

<configuration>
<connectionStrings>
<add name="ApplicationServices" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient" />
<add name="TennisOnlineContext" connectionString="Data Source=|DataDirectory|Tennis.sdf" providerName="System.Data.SqlServerCe.4.0 " />
</connectionStrings>
...
</configuration>

Sorry but it's my first web site where I try to publish… So, please what I'm doing wrong ? Thanks in advance…

Best Answer

Have you tried localhost\SQLEXPRESS? Ensure all of your connection keywords abide by those outlined by Microsoft here.

You can check if a connection string is valid, or indeed build a valid connection string that you can copy, by using the SQL/Database Connection utility that ships with VS2010. In VS2010 goto Tools, Connect to database. This will launch the connection dialog; here you can build and test connection strings. For advance connection features, once in the dialog click Advanced. From the advance dialog you can copy and paste connection strings.

Microsoft have also released this dialog to be freely used and distributed in .NET applications. If you interested in this it can be found here.

I hope this helps.

Related Solutions

C# – Retrieve and use Windows Azure’s connection strings

The connection strings in the Portal allow you to override the connection strings defined in the web.config.

When you're developing locally, you probably use a database located in localhost\SQLExpress or something similar. If you deploy without having set up web.config transformation it would mean that your Web Site running in Windows Azure would still point to localhost\SQLExpress, which isn't something you would want.

The connection strings in the Portal allow you to override existing connection strings which are already defined in the web.config. If your web.config does not contain a connection string with the same name as the one configured in the portal, it will not be added and be accessible at runtime. This might be the issue you're experiencing.

To fix this, simply add a connection string to your web.config file with the same name as the one you have already added to the portal.

Update: Like I already explained in a comment, Windows Azure Web Sites does not physically modify the web.config (source), it does this at runtime. So in order to check which AppSettings and ConnectionStrings are actually available at runtime, try this:

Controller:

public ActionResult Index()
{
  ViewBag.ConnectionStrings =
    ConfigurationManager.ConnectionStrings.Cast<ConnectionStringSettings>();
  ViewBag.AppSettings = ConfigurationManager.AppSettings;
  return View();
}

View:

<h3>ConnectionStrings:</h3>
<ul>
  @foreach (var setting in ViewBag.ConnectionStrings)
  {
    <li>@setting.Name: @setting.ConnectionString</li>
  }
</ul>
<h3>AppSettings:</h3>
<ul>
  @foreach (var s in ViewBag.AppSettings)
  {
    <li>@setting: @System.Configuration.ConfigurationManager.AppSettings[s]</li>
  }
</ul>

C# – update-database: “A network-related or instance-specific error occurred while establishing a connection to SQL Server”

I finally found out. I have a website project and my API in my solution. The problem was that the website was set as startup project. So that entity framework searched the connection string in the website's web.config and not in the api's web.config. Changing the startup project to my API solved the problem.

If you want to have the website project as startup project. Just copy the connection string into the websides web.config.

Nevertheless thanks for everyones help.

Best Answer

Related Solutions

C# – Retrieve and use Windows Azure’s connection strings

C# – update-database: “A network-related or instance-specific error occurred while establishing a connection to SQL Server”

Related Topic