How to implement scheduled backup of CentOS MySQL database

#!/bin/bash

#Save the number of backup files, retain up to 4 files number=4
#Backup save path backup_dir=/db/backup_mysql
#Date dd=`date +%Y-%m-%d-%H-%M-%S`
#Backup tool tool=mysqldump
#Username username=root
#passwordpassword=yourpassword
#Database to be backed up database_name=mydb

#If the folder does not exist, create it if [ ! -d $backup_dir ];
then
  mkdir -p $backup_dir;
fi

#Simple way to write mysqldump -u root -p123456 users > /root/mysqlbackup/users-$filename.sql
$tool -h127.0.0.1 -u $username -p$password $database_name > $backup_dir/$database_name-$dd.sql

#Write to create backup log echo "create $backup_dir/$database_name-$dd.dupm" >> $backup_dir/log.txt

#Find the backup that needs to be deleted delfile=`ls -l -crt $backup_dir/*.sql | awk '{print $9 }' | head -1`

#Judge whether the current number of backups is greater than $number
count=`ls -l -crt $backup_dir/*.sql | awk '{print $9 }' | wc -l`

if [ $count -gt $number ]
then
 #Delete the earliest generated backup and keep only number of backups rm $delfile
 #Write the delete file log echo "delete $delfile" >> $backup_dir/log.txt
fi