将SQL Server数据库连接到ASP.NET应用程序版本

Question

I have an ASP.NET application using Entity Framework. I'm trying to release it on the hosting, but I get following errors:

[Win32Exception (0x80004005): The system cannot find the file specified]

[SqlException (0x80131904): 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: 52 - Unable to locate a Local Database Runtime installation. Verify that SQL Server Express is properly installed and that the Local Database Runtime feature is enabled.)]

I set the connection string as shown on the hosting website and created database. How should I configure this to get rid of this error?

Answer 1

Exception due to your web application is not able to connect SQLSERVER instance. Following are options to resolve the problem:

1. Check if your service is running up

Go to All Programs > Microsoft SQL Server 2012 > Configuration Tools > SQL Server Configuration Manager > SQL Server Services Check to make sure SQL Server service status is Running.

or

Open run command console(Windows + R) then type services.msc. You will all services in your system and check SqlServer (Sqlexpress) service is running mode.

2. Make sure your database engine is configured to accept remote connections

Start > All Programs > SQL Server 2005 > Configuration Tools > SQL Server Surface Area Configuration Click on Surface Area Configuration for Services and Connections Select the instance that is having a problem > Database Engine > Remote Connections Enable local and remote connections Restart instance using services.msc in run command window(discussed in #1)

3. Enable TCP/IP in SQL Server Configuration

Go to All Programs >> Microsoft SQL Server 2012 > Configuration Tools >> SQL Server Configuration Manager >> Select TCP/IP

Right Click on TCP/IP >> Click on Enable

Then restart the sqlserver service using services.msc in run command window(discussed in #1)

Lastly you need to check that it might be server firewall setting because sometimes firewall blocks incoming request from other servers. And also check you are providing correct connection string means username, password, server etc.

Thank You..

Answer 2

<connectionStrings>
        <add name="conn2" connectionString="Data   Source=192.?.?.?\your_db_instance;Initial Catalog=your_db_schema;Integrated Security=False;User ID=your_db_login;Password=??????" providerName="System.Data.SqlClient"/>
</connectionStrings>

Answer 3

As you are able to connect from SQL SMS, try to connect with the same remote parameters from Server Explorer window in Visual Studio as well. Click "add connection" on "Data Connections": Add Connection in Server Explorer . After the connection being created, get the connection string from the properties window by right clicking on the connection object. Use this connection string in the hosted web.config file.