How to use the batching and batching termination filter descriptors in BCS .NET Connectivity solutions

Question

I know about this post on BCS paging: Paging and sorting with BCS and have implemented a similar approach in a BCS solution. However, what I'm really looking for is a complete example showing how to use the batching and batching termination filter descriptors in a BCS .NET Connectivity solution. The MSDN post: http://msdn.microsoft.com/en-us/library/ee557835.aspx is incomplete. If anyone knows of a source (blog, article, book, chm, post-it note) that demonstrates exactly how to use these batching filter descriptors, please let me know where to find it.

Thanks!

Answer 1

You can try this:

<Method Name="GetItems" LobName="GetItems" IsStatic="false">
          <FilterDescriptors>
            <FilterDescriptor Name="BatchingStateCookie" Type="Batching">
              <Properties>
                <Property Name="BatchingCookie" Type="System.String">Cookie</Property>
              </Properties>
            </FilterDescriptor>
            <FilterDescriptor Name="HasMoreBatches" Type="BatchingTermination">
              <Properties>
                <Property Name="CaseSensitive" Type="System.Boolean">false</Property>
                <Property Name="Comparator" Type="System.String">!=</Property>
                <Property Name="TerminationValue" Type="System.String">true</Property>
              </Properties>
            </FilterDescriptor>
          </FilterDescriptors>
          <Parameters>
            <Parameter Name="cookie" Direction="InOut">
              <TypeDescriptor Name="cookieTypeDescriptor" TypeName="System.String" AssociatedFilter="BatchingStateCookie"/>
            </Parameter>
            <Parameter Name="hasmore" Direction="Out">
              <TypeDescriptor Name="hasmoreTypeDescriptor" TypeName="System.String" AssociatedFilter="HasMoreBatches"/>
            </Parameter>

and in .NET:

int batch_size = 1000;
public MyItem[] GetItems(ref string cookie, out string hasmore)
{

    if (cookie == null) {
        // we are in first batch
        // do some initialization if needed
    }
    MyItem[] items = new MyItem[batch_size];
    ;
    hasmore =  GetItemsFromDatabase(cookie, items) > 0 ? "true" : "false";
    cookie = items[0].Id; // or something else you need to determine what to bring in the next batch
    return items;
}