IM using BCS connecting to local DB from SharePoint site in designer creating external lists but i'm facing error as below :
Cannot connect to the LobSystem (External System). Reason: '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 Database runtime installation. Verify that SQL Server Express is properly installed and the Local Database Runtime Feature is enabled.)'