您不能将.bak文件附加到实例; .bak文件是SQL备份，因此您必须从.bak文件恢复到您的实例。



请参阅使用SSMS恢复数据库备份 [ ^ ]

You cannot "attach a .bak file" to an instance ; .bak files are SQL backups, thus you have to restore from the .bak file to your instance.

Please see Restore a Database Backup Using SSMS[^]