portal.cs

SPSiteDataQuery query =  new SPSiteDataQuery();
query.ViewFields = "<FieldRef Name=\"Title\" /><FieldRef Name=\"DueDate\" />";
query.Query = @"<Where>
		 <And>
		   <Eq>
		     <FieldRef Name='AssignedTo'/>
		      <Value Type='User'>" +
                       SPContext.Current.Web.CurrentUser.Name
		     + @"</Value>
		   </Eq>
		   <Neq>
			<FieldRef Name='Status'/>
		        <Value Type='Choice'>Completed</Value>
		  </Neq>
		</And>
		</Where>";
query.Lists = "<Lists ServerTemplate=\"107\" MaxListLimit=\"0\"/>"; //Tasks Lists
query.Webs = "<Webs Scope=\"Recursive\" />";

//query.RowLimit = 100;

PortalSiteMapProvider ps = PortalSiteMapProvider.CurrentNavSiteMapProviderNoEncode;
PortalWebSiteMapNode pNode = ps.FindSiteMapNode(curWeb.ServerRelativeUrl) as PortalWebSiteMapNode;

DataTable results = ps.GetCachedSiteDataQuery(pNode, query, SPContext.Current.Web);