Overwrote database with old mysql dump. How can I restore it with a more recent backup
You won't get a much better answer than here.
Basically, the part of this document that you want is here:

Restoring your MySQL Database
Above we backup the Tutorials database into tut_backup.sql file. To
re-create the Tutorials database you should follow two steps:

Create an appropriately named database on the target machine


If, as is your case, you only wish to restore 1 database of many in a schema, pay particular attention to the line above - it could save you a lot of time and trouble!


Load the file using the mysql command:

$ mysql -u [uname] -p[pass] [db_to_restore] &lt; [backupfile.sql]

Note in particular the space between -u and uname and the missing space between -p and your password. This threw me for quite a while.
If you're in any sort of DBA role, this really should be your bread and butter. Many backup strategies also feed the backup into gzip or similar. The way to restore these is also covered.

To restore compressed backup files you can do the following:
gunzip &lt; [backupfile.sql.gz] | mysql -u [uname] -p[pass] [dbname]

Again, if you are in any sort of DBA role, you should be doing this at least every three months in order to ensure that all of your backup steps

a) work, and

b) can be performed efficiently with minimum service disruption to business/users.