Common Cause 1
SQL Server Manager is not running (not started) or is not installed when SQL database is installed;
Workaround: Uninstall the database and reinstall it, and you need to start the SQL Service Manager (SQL Server Manager defaults to boot after the database is installed);
Common Cause 2
Limitations of computer security protection, errors in SQL Server security settings, or security restrictions on the operating system;
Workaround: Properly set security software, especially Windows Firewall settings, and then reset the SQL database safety properties; The above content is to the database connection failure how to do this kind of parking system common fault related introduction, but it is recommended that the professionals do not operate on their own, so as not to lose data.