SQL Server Error: System.Data.SqlClient.SqlException

The following error occurred while deploying the ASP. MVC4 project to a new machine:

System.Data.SqlClient.SqlException

The specific contents are as follows:

System.Data.SqlClient.SqlException:"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or could not be accessed. Verify that the instance name is correct, and that SQL Server is configured to allow remote connections. (provider:named Pipes provider, error:40-Unable to open connection to SQL Server) "

It is obvious that the database could not be found.

As a workaround, modify the database connection string to:

Data source=.\sqlexpress

Description

I used the. syntax to simply let it find the local database by default, but missing the sqlexpress. Add to it.

SQL Server Error: System.Data.SqlClient.SqlException