The simple way is to run mysqlcheck -r -A -p r:Repair A:All databases p:Prompt for password.

If you only want to do one database drop the -A and put the database name on the end.

This tends to correct most common errors, if it's well and truly corrupted you can look at myismchk to manually repair each table as long as they're myisam.

You can restore corrupted table from backup, if "mysqlcheck" is not successful

Thank you SteveWilson !