# Object Relational Hierarchy Mode

| RELATED VIDEOS                                                                                                                                                                                                                                                                                        |                                                                                                                                                                                                                                |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [Creating Object Relational Hierarchies in RadGridView](http://tv.telerik.com/watch/winforms/creating-object-relational-hierarchies-in-radgridview-for-winforms)<br>In this video, you will learn how to automatically and manually create object relational hierarchies in RadGridView for WinForms. | ![WinForms RadGridView Relational Hierarchy Mode Tutorial](https://www.telerik.com/products/winforms/documentation/assets/cecb516efbcdfc78b67f30d2478121c7/gridview-hierarchical-grid-object-relational-hierarchy-mode005.png) |

## Auto Generating Hierarchy Mode

The Object-Relational Hierarchy mode is used to show hierarchy based on a complex `IList` (IEnumarable) object that contains inner `ILits` (IEnumerable) properties.

In order to create an Object-Relational Hierarchy automatically in this scenario, you must set only the DataSource and the AutoGenerateHierarachy properties of RadGridView.

Here is an example with an entity model using the Northwind database:

![WinForms RadGridView Generating Hierarchy Mode](https://www.telerik.com/products/winforms/documentation/assets/296216946ee29b07268e1cf0cad30a58/gridview-hierarchical-grid-object-relational-hierarchy-mode001.png)

```C#
private void AutoGenerateObjectRelationHierarchyMode_Load(object sender, EventArgs e)
{
    NorthwindEntities entities = new NorthwindEntities();
    var query = from suppliers in entities.Suppliers select suppliers;

    this.radGridView1.DataSource = query.ToList();
    this.radGridView1.AutoGenerateHierarchy = true;
}
```

```VB.NET
Private Sub AutoGenerateObjectRelationHierarchyMode_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim entities As New NorthwindEntities()
    Dim query = From suppliers In entities.Suppliers Select suppliers

    Me.RadGridView1.DataSource = query.ToList()
    Me.RadGridView1.AutoGenerateHierarchy = True
End Sub
```

![WinForms RadGridView Auto Generating Hierarchy Mode](https://www.telerik.com/products/winforms/documentation/assets/4e640cd71f8464cb7f319e5cc7aa3b13/gridview-hierarchical-grid-object-relational-hierarchy-mode002.png)

## Manually Generating Hierarchy Mode

The Object-Relational hierarchy mode can be setup manually by creating the child `GridViewTemplate` and adding `GridViewRelation` between `GridViewTemplates`. This special relation should contain the name of the property that belongs to the parent object and that returns an `IList` (IEnumerable) of sub-objects. RadGridView uses the name of the property to load the necessary data for the child `GridViewTemplate` when the user expands a parent row.

> note In this mode only the DataSource of parent GridViewTemplate or RadGridView control must be set to a collection of custom business object or ORM data objects.

The following example demonstrates how you can manually build an object-relational hierarchy using the "Customers" entity model from the Northwind database:

![WinForms RadGridView Manually Generating Hierarchy Mode](https://www.telerik.com/products/winforms/documentation/assets/ad52a39964febf1df4b1783e75edd7ee/gridview-hierarchical-grid-object-relational-hierarchy-mode006.png)

```C#
void ManualGenerateObjectRelationalMode_Load(object sender, EventArgs e)
{
    NorthwindEntities entities = new NorthwindEntities();
    var query = from customers in entities.Customers select customers;

    GridViewTemplate childTemplate = CreateChildTemplate();

    GridViewRelation relation = new GridViewRelation(this.radGridView1.MasterTemplate, childTemplate);
    relation.ChildColumnNames.Add("Orders");
    this.radGridView1.Relations.Add(relation);
    this.radGridView1.DataSource = query.ToList();
}

private GridViewTemplate CreateChildTemplate()
{
    GridViewTemplate childTemplate = new GridViewTemplate();
    this.radGridView1.Templates.Add(childTemplate);

    GridViewTextBoxColumn column = new GridViewTextBoxColumn("OrderDate");
    childTemplate.Columns.Add(column);
    column = new GridViewTextBoxColumn("Freight");
    childTemplate.Columns.Add(column);
    column = new GridViewTextBoxColumn("ShipName");
    childTemplate.Columns.Add(column);
    column = new GridViewTextBoxColumn("ShipCountry");
    childTemplate.Columns.Add(column);
    column = new GridViewTextBoxColumn("ShipCity");
    childTemplate.Columns.Add(column);
    column = new GridViewTextBoxColumn("ShipAddress");
    childTemplate.Columns.Add(column);
    childTemplate.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;

    return childTemplate;
}
```

```VB.NET
Private Sub ManualGenerateObjectRelationalMode_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim entities As New NorthwindEntities()
    Dim query = From customers In entities.Customers Select customers

    Dim childTemplate As GridViewTemplate = CreateChildTemplate()

    Dim relation As New GridViewRelation(Me.RadGridView1.MasterTemplate, childTemplate)
    relation.ChildColumnNames.Add("Orders")
    Me.RadGridView1.Relations.Add(relation)
    Me.RadGridView1.DataSource = query.ToList()

End Sub

Private Function CreateChildTemplate() As GridViewTemplate
    Dim childTemplate As New GridViewTemplate()
    Me.radGridView1.Templates.Add(childTemplate)

    Dim column As New GridViewTextBoxColumn("OrderDate")
    childTemplate.Columns.Add(column)
    column = New GridViewTextBoxColumn("Freight")
    childTemplate.Columns.Add(column)
    column = New GridViewTextBoxColumn("ShipName")
    childTemplate.Columns.Add(column)
    column = New GridViewTextBoxColumn("ShipCountry")
    childTemplate.Columns.Add(column)
    column = New GridViewTextBoxColumn("ShipCity")
    childTemplate.Columns.Add(column)
    column = New GridViewTextBoxColumn("ShipAddress")
    childTemplate.Columns.Add(column)
    childTemplate.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill

    Return childTemplate
End Function
```

![WinForms RadGridView Generating Hierarchy Mode](https://www.telerik.com/products/winforms/documentation/assets/b678997da01c3024be3214d91b6626f9/gridview-hierarchical-grid-object-relational-hierarchy-mode004.png)

> important As you can notice, we can perform all data operations on the child templates – grouping, sorting and filtering. RadGridView processes only the amount of data required for a particular data operation (lazy data loading). This provides us with better performance and small memory footprint.

> note Since the R3 2015 SP1 release **RadGridView** supports CRUD operations for its inner levels. The **AutoUpdateObjectRelationalSource** defines whether CRUD should be managed by the API or not, by default its value is set to *true* . In case one needs to handle these operations manually the property needs to be set to *false* .

## See Also

* [Binding to Hierarchical Data Automatically](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/binding-to-hierarchical-data-automatically)

* [Binding to Hierarchical Data Programmatically](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/binding-to-hierarchical-data-programmatically)

* [Binding to Hierarchical Data](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/binding-to-hierarchical-data)

* [Creating hierarchy using an XML data source](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/creating-hierarchy-using-an-xml-data-source)

* [Hierarchy of one to many relations](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/hierarchy-of-one-to-many-relations)

* [Load-On-Demand Hierarchy](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/load-on-demand-hierarchy)

* [Self-Referencing Hierarchy](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/self-referencing-hierarchy)

* [Tutorial Binding to Hierarchical Data](https://www.telerik.com/products/winforms/documentation/controls/gridview/hierarchical-grid/tutorial-binding-to-hierarchical-data)