MVC 多条件查询，带分页的

这是绑定的代码，获取前台 Request.Form["name"]，后怎么增加查询条件

            page = page == null ? 1 : page;
            rows = rows == null ? 1 : rows;
            List<TBL_M_SECURITY_STAFF> list = db.TBL_M_SECURITY_STAFF.OrderBy(a => a.Security_Staff_ID).Skip((Convert.ToInt32(page) - 1) * Convert.ToInt32(rows)).Take(Convert.ToInt32(rows)).ToList();
            var json = new
            {
                total = db.TBL_M_SECURITY_STAFF.Count(),
                rows = list.Select(a => a)

            };
            return Json(json, JsonRequestBehavior.AllowGet);

if(!string.IsNullOrEmpty(Request.Form["name"]))
{
list = list.where(x=>x.name == Request.Form["name"]);
}

 var query = db.TBL_M_SECURITY_STAFF;
if(!string.IsNullOrEmpty(Request.Form["name"]))
query =query.Where(x => x.name == Request.Form["name"]);
f(!string.IsNullOrEmpty(Request.Form["sex"]))
query =query.Where(x => x.name == Request.Form["sex"]);
...
List<TBL_M_SECURITY_STAFF> list = query.OrderBy(a => a.Security_Staff_ID).Skip((Convert.ToInt32(page) - 1) * Convert.ToInt32(rows)).Take(Convert.ToInt32(rows)).ToList();