Simple Bash script to backup your MySQL database. Don't forget it to make it executable by using chmod +x.

dump_db.sh

#!/bin/bash
now=$(date +"%d_%m_%Y")
password="yourpassword"
db_name="yourdbname"
file_name="db_dump_$now.sql"
echo "Backing up the db to $file_name"
mysqldump -u root -p"$password" "$db_name" > "$file_name"