passing multiple values from gridview is very easy

You can pass single/multiple query string using HyperLInkField
Pass data field name in DataNavigateUrlFields which you wnat to pass value in query stringex:
DataNavigateUrlFields=”subject,query”
here subject and query both are differenct data field those are comming from database.
and write the page name in DataNavigateUrlFormatString where you want to pass query string value.
ex:
DataNavigateUrlFormatString = “~/Pages/default.aspx?UserName={0}&GameTitle={1}”
Take hyperlink field like with this properties