如何腳本備份各個分庫

#! /bin/sh
if [ $# -lt 1 ];then
	echo "error.. need args"
	exit
fi

if [ "$1"x != "back"x ];then
	echo "usage back_db.sh back"
	exit
fi

mysqldump -uxxxx -pxxxx db_name>db_name.bak

for dbId in `seq 0 9`
do
    mysqldump -uxxxx -pxxxx db_${dbId}>db_${dbId}.bak
done