Referring to the document:
It is suggested that you can back up a MySQL database using the command:
mysqldump --user=wikidb_user --password=wikidb_userpassword wikidb > file.sql
but this isn't entirely accurate. This will not preserve the name of the database name of the wiki. A more robust backup would be:
mysqldump --user=wikidb_user --password=wikidb_userpassword --databases wikidb > file.sql
which tells mysqldump to also include a CREATE DATABASE clause as the first step in the script. Why on earth does the documentation suggest this method?