There isn’t a simple command to rename a mysql database. You just need to create a new database and then rename all the tables like so:
RENAME TABLE old_db.table_name TO new_db.table_name
There is also an alternative method by dumping the old database and importing it again like so:
mysqldump -v oldDatabase > oldDump.sql mysqladmin create newDatabase mysql newDatabase < oldDump.sql
I have found the second option to be alot faster both in time and on the disk.