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1248600
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2009-08-08T11:21:07.657
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2009-08-08T13:55:55.200
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2009-08-08T13:55:55.200
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1311500
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1311500
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1248592
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2
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Because you're setting a <code>DataSet</code> as <code>DataSource</code> and then casting it to <code>DataTable</code> with the operator <a href="http://dotnetbutchering.blogspot.com/2008/08/net-difference-between-casting-and-as.html" rel="nofollow noreferrer"><code>as</code></a>. The 'as' operator in C# is a tentative cast - if it's impossible to cast (types are not compatible) instead of throwing an exception as the direct cast the 'as' operator sets the reference to null. If you only have one datatable in your dataset then you can get the first element like this: <pre><code>ds.Tables[0]; </code></pre> ... or use the name of the table: <pre><code>ds.Tables["myTable"]; </code></pre> in your case you can try... <pre><code>DataTable dt = GridView1.DataSource.Tables[0] as DataTable; </code></pre> Hope it helps! EDIT: with regards to your sorting problem (once you get the datatable): <pre><code>if (dt != null) { dt.DefaultView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection); GridView1.DataBind(); } </code></pre> You can do this because dt is a reference to the exact same object that's already set as DataSource for your grid. It should do the trick - if not there's smt else I am missing (such as we're sorting the wrong table meaning you have more than one table in the DataSet). EDIT: had a look at your code. I don't know exactly when GetValues gets fired but I suspect it's causing your problem (I think it might be overriding your sorting or smt along those lines). If you comment out FillDataSource from getValues and modify your PageLoad to do this: <pre><code> void Page_Load(Object sender, EventArgs e) { // Load data only once, when the page is first loaded. if (!IsPostBack) { Session["myDataSet"] = FillDataSet(); } } </code></pre> then in your sort method you retrieve the DataSource like this: <pre><code>DataTable dt = ((DataSet)Session["myDataSet"]).Tables[0]; </code></pre> Also you can retrieve the DataSet from session in your pagination handler method. You should also notice an improvement in performance since you're retrieving the stuff form the db just once. Give it a shot!
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.