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FederationDataSourceBase.Queries Property

Provides access to federated queries contained in the data source.

Namespace: DevExpress.DataAccess.DataFederation

Assembly: DevExpress.DataAccess.v22.2.dll

NuGet Package: DevExpress.DataAccess


public QueryNodeCollection Queries { get; }

Property Value

Type Description

A collection of federated data queries.


This code snippet demonstrates how to create a federated data source that contains two queries. The SelectNodeBuilder‘s Fluent API is used to construct a federated query.


The complete sample project How to Create a Federated Data Source at Runtime is available in the DevExpress Examples repository.

using DevExpress.DataAccess.DataFederation;
// ...
    FederationDataSource federation = new FederationDataSource();

    Source sourceProducts = new Source("Products", CreateSqlDataSource(), "Products");
    Source sourceOrderDetail = new Source("OrderDetail", CreateExcelDataSource("SalesPerson.xlsx", "Data"));
    Source sourceHeader = new Source("OrderHeader", CreateExcelDataSource("OrderHeaders.xlsx", "OrderHeader"));

    SelectNode query1 = sourceProducts.From().Select("ProductName", "QuantityPerUnit", "UnitsInStock")
        .Join(sourceOrderDetail, "[Products.ProductName] = [OrderDetail.ProductName]")

    SelectNode query2 = sourceHeader.From().Select("OrderID", "Status", "Description")
        .Join(sourceOrderDetail, "[OrderHeader.OrderID] = [OrderDetail.OrderID]")
        .Select("Quantity", "Extended Price")

    federation.Queries.AddRange(new[] { query1, query2 });
See Also