This article assumes a few things before you run the command:
You are running the command inside the directory where your backups reside
All of the SQL backup files are decompressed and filename ends in .sql
The databases have already been created on the server
Run this as one single command:
for dbfile in *.sql
echo "Importing database: $db from $dbfile"
mysql "$db" < "$dbfile"
echo "Done importing $db"