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Properties without UpdateCheck="Always" have no value when accessed through LinqDataSource event handler RRS feed

  • Question

  • I have a practise of setting UpdateCheck="Never" for most table properties in the DBML file. This is because I don't want the extra overhead from concurrency checking (see Turn Optimistic Concurrency Off Unless You Need It)

    However, I have noticed a strange side effect of doing this. Can anyone explain this?

    If I am updating a particular entity through a LinqDataSource (e.g. a ListView bound to a LinqDataSource) and I check the object's new state inside the LinqDataSource's OnUpdating (or OnUpdated) event, like this:

                SalesHistory sh = (SalesHistory)e.NewObject;

    ... then any properties that have UpdateCheck="Never" have no value (e.g. integer's have zero value). This is a big problem, because the database update requires this data!

    However, if inside the same method I get the same entity from the database with a LINQ query, then the object has complete property values, e.g.

                var test = (from s in _dc.SalesHistories where s.salereport_id == 67664 select s).Single();

    There just seems to be a problem getting access to the property values inside LinqDataSource event handlers. The property values are fine if accessed through an Eval function in the ListView, e.g.

    <asp:LinkButton ID="lnkViewSale" runat="server" OnClick="lnkViewSale_Click"
        CommandName='<%# Eval("salereport_id") %>' Text="Details" />
    

    Is there a good explanation for this, and is there any way to get full access to the property values in the event handlers without  turning on the UpdateCheck?

     

    Tuesday, October 5, 2010 10:23 AM

All replies

  • Noticed a second strange thing: properties that have IsDbGenerated="true", in addition to requiring UpdateCheck="Always", also have to have AutoSync="OnInsert" set. If AutoSync="Always" then the property value is also missing inside the LinqDataSource event handlers.
    Tuesday, October 5, 2010 10:50 AM