mysql-linux regularly backs up the mysql database

sh script

# !/bin/bash 
db_user= " database user name " 
db_passwd = " database password " 
db_name = " database name " 
cd /home/backup/mysql/ bakmysql
echo "you are in bakmysql directory now"
mv yanheap2* /home/backup/mysql/bakmysqlold
echo "Old databases are moved to bakmysqlold folder"
backup_dir="/home/backup/mysql/bakmysql"
time=$(date +"%Y-%m-%d")
mysqldump -u$db_user -p$db_passwd $db_name  > "$backup_dir/$db_name"-"$time.sql"
echo "your database backup successfully completed"
SevenDays=$(date -d -30day  +"%Y-%m-%d")
if [ -f /home/backup/mysql/bakmysqlold/$db_name-$SevenDays.sql ]
then
rm -rf /home/backup/mysql/bakmysqlold/$db_name-$SevenDays.sql
echo "you have delete 30days ago bak sql file "
else
echo "30days ago bak sql file not exist "
echo "bash complete"
fi