备份数据存放在 /home/dbback/sql/ 目录
```
#!/bin/bash

#数据库 信息
host=127.0.0.1
user=root
pass=123456
db=dc_product

function bakDb(){

host=$1
user=$2
pass=$3
db=$4

start=`date +%s`
time=$(date +%Y%m%d)
time2=$(date +%Y%m%d_%H%M%S)

dbsavedir=/home/dawnco/web/sql/$time
dbsavepath=$dbsavedir/${db}.sql
mkdir -p $dbsavedir

#back db
mysqldump -u${user} -p${pass} $db > $dbsavepath

end=`date +%s`
dif= expr $end - $start
echo $dif
}

bakDb $host $user $pass $db

```