Use this bash script to backup mysql databases

Mysql-backup.sh

#!/bin/bash

# Backup Destination Folder
DEST=/backup
date=$(date +"%I:%M%p-%d-%m-%Y")

DATABASES=$(mysql -e "SHOW DATABASES;" | tr -d "| " | grep -v Database)

[ ! -d $DEST ] && mkdir -p $DEST

for db in $DATABASES; do
  FILE="${DEST}/$db-$date.sql"
  FILEDATE=

  # Be sure to make one backup per day
  [ -f $FILE ] && FILEDATE=$(date -r $FILE +"%F")

  [ -f $FILE ] && mv "$FILE" "${FILE}.old"
  mysqldump --single-transaction --routines --quick -B $db > "$FILE"

  # Delete files older than 3 days
  find $DEST/* -mtime +3 -exec rm {} \;

done