shell script for backup mysql database

db_backup.sh

backup_parent_dir="/Applications/MAMP/htdocs/test"
mysql_user="root"
mysql_password="root"
db_name="cms"
db_port="8889"
days=3
excluded_tables=(
    log
)
mysql_executable_folder="/Applications/MAMP/Library/bin"

echo exit | ${mysql_executable_folder}/mysql -P $db_port --user=$mysql_user --password=$mysql_password -B 2>/dev/null
if [ "$?" -gt 0 ]; then
  exit 1
fi

ignored_tables_as_string=''
for table in "${excluded_tables[@]}"
do :
   ignored_tables_as_string+=" --ignore-table=${db_name}.${table}"
done

backup_date=`date +%Y_%m_%d_%H_%M`
backup_dir="${backup_parent_dir}/${backup_date}"
mkdir -p "${backup_dir}"
chmod 700 "${backup_dir}"

${mysql_executable_folder}/mysqldump -P $db_port --user=$mysql_user --password=$mysql_password ${ignored_tables_as_string} $db_name | gzip -9 > "${backup_dir}/$db_name.sql.gz"
chmod 600 "${backup_dir}/$db_name.sql.gz"

find $backup_parent_dir/* -type d -mtime +$days -exec rm -rf {} \;