That would be up to your host. They
should make daily backups of your data. If they do then...
Click on Backups on your cPanel home page menu. Then, the second section should say something along the lines of "Download a MySQL Database Backup". Just click on the database name below that corrosponds to the corrupted database(s) and you should be able to download them. Then, on the right, click on "Browse" under "Download a MySQL Database Backup" and select the downloaded database. Then upload it. It should automatically update the corrupted databases with the backuped ones.
Hope that helps
.