Resolve MySQL Database restore error: (mysql error code:1005 errno 121)

The reason is roughly that the primary key must be unique, that is, where the database may exist and where the restored database is duplicated, a restriction that Foreign keys should is uniquely named throughout the DB, an effective way is to clear the original database and then create the restore.

I this time the reason is the newly installed MySQL ibdata1 backup file was replaced by my previous database ibdata1 backup file, was intended to be forced by this method to restore, but did not do, the results of the backup SQL file to restore the database of the previous data also error, The replacement of the Ibdata1 file can be restored back to resolve.