DashboardFederationDataSource Class

A federated data source that retrieves data from different data sources.

Namespace: DevExpress.DashboardCommon

Assembly: DevExpress.Dashboard.v20.1.Core.dll

Declaration

public class DashboardFederationDataSource :
    FederationDataSourceBase,
    IDashboardDataSource,
    IDashboardComponent,
    IComponent,
    IDisposable,
    ISupportInitialize,
    ISupportPrefix,
    IDashboardDataSourceInternal,
    ICloneable<DashboardFederationDataSource>,
    IAssignable<DashboardFederationDataSource>,
    IQueryDataSource<QueryNode>,
    IExternalSchemaConsumer
Public Class DashboardFederationDataSource
    Inherits FederationDataSourceBase
    Implements IDashboardDataSource,
               IDashboardComponent,
               IComponent,
               IDisposable,
               ISupportInitialize,
               ISupportPrefix,
               IDashboardDataSourceInternal,
               ICloneable(Of DashboardFederationDataSource),
               IAssignable(Of DashboardFederationDataSource),
               IQueryDataSource(Of QueryNode),
               IExternalSchemaConsumer

Remarks

You can create a query that combines multiple data sources to provide uniform access. This query forms the federated data source which operates with the source-specific query language, translates the queries, and processes the results to supply a dashboard with data. A federated data source does not support OLAP data sources.

TIP

Demo: Data Federation

Requires installation of Universal Subscription v20.1. Download

Create a DashboardFederationDataSource instance and add it to the Dashboard.DataSources collection.

The data source obtains its data from federated queries contained in the Queries collection.

NOTE

In Async mode, if the FederationDataSource includes the DashboardObjectDataSource, make sure that the DashboardObjectDataSource gets data in the AsyncDataLoading event handler and do not call the DashboardObjectDataSource.Fill and FederationDataSource.Fill methods.

Examples

using DevExpress.DashboardCommon;
using DevExpress.DataAccess.ConnectionParameters;
using DevExpress.DataAccess.DataFederation;
using DevExpress.DataAccess.Excel;
using DevExpress.DataAccess.Sql;
// ...
DashboardFederationDataSource federatedDS = CreateFederatedDataSource(sqliteDataSource, exceldataSource, objectDataSource);
dashboard.DataSources.Add(federatedDS);

private static DashboardFederationDataSource CreateFederatedDataSource(DashboardSqlDataSource sqliteDataSource, DashboardExcelDataSource exceldataSource, DashboardObjectDataSource objectDataSource)
{
    DashboardFederationDataSource federationDS = new DashboardFederationDataSource();
    Source sqlSource = new Source("sqlite", sqliteDataSource, "SQLite Orders");
    Source excelSource = new Source("excel", exceldataSource, "");
    Source objectSource = new Source("SalesPersonDS", objectDataSource, "");

    #region Use-API-to-create-a-query
    SelectNode mainQueryCreatedByApi = new SelectNode();

    SourceNode excelSourceNode = new SourceNode(excelSource, "ExcelDS");
    SourceNode objectSourceNode = new SourceNode(objectSource, "ObjectDS");
    SourceNode sqliteSourceNode = new SourceNode(sqlSource, "SQLite Orders");

    mainQueryCreatedByApi.Alias = "FDS-Created-by-API";
    SourceNode root = new SourceNode(sqlSource, "SQLite Orders");
    mainQueryCreatedByApi.Root = root;
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "SalesPerson", Node = objectSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "Weight", Node = objectSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "CategoryName", Node = excelSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "ProductName", Node = excelSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "OrderDate", Node = sqliteSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "ShipCity", Node = sqliteSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "ShipCountry", Node = sqliteSourceNode });
    mainQueryCreatedByApi.Expressions.Add(new SelectColumnExpression() { Name = "Extended Price", Node = excelSourceNode });
    mainQueryCreatedByApi.SubNodes.Add(new JoinElement(excelSourceNode, JoinType.Inner, "[ExcelDS.OrderID] = [SQLite Orders.OrderID]"));
    mainQueryCreatedByApi.SubNodes.Add(new JoinElement(objectSourceNode, JoinType.Inner, "[ObjectDS.SalesPerson] = [ExcelDS.Sales Person]"));
    #endregion

    #region Use-NodedBuilder-to-create-a-query
    SelectNode mainQueryCreatedByNodeBuilder =
        sqlSource.From()
        .Select("OrderDate", "ShipCity", "ShipCountry")
        .Join(excelSource, "[excel.OrderID] = [sqlite.OrderID]")
            .Select("CategoryName", "ProductName", "Extended Price")
            .Join(objectSource, "[SalesPersonDS.SalesPerson] = [excel.Sales Person]")
                .Select("SalesPerson", "Weight")
                .Build("FDS-Created-by-NodeBulder");
    #endregion

    federationDS.Queries.Add(mainQueryCreatedByNodeBuilder);
    federationDS.Queries.Add(mainQueryCreatedByApi);

    federationDS.CalculatedFields.Add("FDS-Created-by-NodeBulder", "[Weight] * [Extended Price] / 100", "Score");

    federationDS.Fill(new DevExpress.Data.IParameter[0]);
    return federationDS;
}

Inheritance

Object
MarshalByRefObject
Component
DevExpress.DataAccess.DataComponentBase
FederationDataSourceBase
DashboardFederationDataSource
See Also