After installing SQL, I found that errors 40 and 53 were reported. As a novice, I was also confused. Obviously everything was installed according to the default and the next step. Why did the problem occur when connecting to the database? ?
Later, after investigation, it was found that one of the IPs in the sql configuration management needed to be set as the local IP. The detailed process is as follows, because it was also learned from others, so it is a semi-reprint, after all, I will do it myself.
During installation, the user selected to add the current user, so the authentication for logging into the database is based on the Windows user authentication, and the error content is as follows.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or could not be reached. Please verify that the instance name is correct and that SQL Server is configured to allow remote connections. (proveder: Named Pipes Provider, error: 40 - Could not open connection to SQL Server) (Microsoft SQL Server, error: 53)"
Start Menu -> All Programs -> Microsoft SQL Server 2008 -> Configuration Tools ->
SQL Server Configuration Manager->Network Configuration->MSSQLSERVER2008->Double-click "TCP/IP"->Protocol->Enabled->Select "Yes"
SQL Server Configuration Manager->Network Configuration->MSSQLSERVER2008->Double-click "TCP/IP"->IP Address->IPAll->TCP Port->Enter "1433" and click OK
Start Menu->All Programs->Microsoft SQL Server 2008->Configuration Tools->SQL Server Configuration Manager->SQL Server Services->SQL Server (MSSQLSERVER2008)->Right Click Restart