QueryBuildingExtensions.Transform(Source) Method

Creates a TransformationNodeBuilder object that allows you to apply transformation operations to an element of the Federation Data Source.

Namespace: DevExpress.DataAccess.DataFederation

Assembly: DevExpress.DataAccess.v21.1.dll

NuGet Packages: DevExpress.DataAccess, DevExpress.Win.Design

Declaration

C#

public static TransformationNodeBuilder Transform(
    this Source source
)

VB.NET

<ExtensionAttribute>
Public Shared Function Transform(
    source As Source
) As TransformationNodeBuilder

Parameters

Name	Type	Description
source	Source	An element of the Federation Data Source.

Returns

Type	Description
TransformationNodeBuilder	An object that allows you to apply transformation operations.

Example

The following example demonstrates how to unfold a data source’s Products array:

Show JSON Data

[
    {
        "CategoryID": 1,
        "Products":
        [
            {
                "ProductName": "Chai",
                "UnitPrice": 18
            },
            {
                "ProductName": "Chang",
                "UnitPrice": 19
            }
        ]
    },
    {
        "CategoryID": 2,
        "Products":
        [
            {
                "ProductName": "Ikura",
                "UnitPrice": 31
            },
            {
                "ProductName": "Konbu",
                "UnitPrice": 6
            }
        ]
    }
]

C#

using DevExpress.DataAccess.DataFederation;
using DevExpress.DataAccess.Json;
// ...
var source = new Source("Products", jsonDataSource);

var query = source
    .Transform()
    .UnfoldColumn("Products")
    .Build("ProductsUnfolded");

var federation = new FederationDataSource() {
    Queries = { query }
};

VB.NET

Imports DevExpress.DataAccess.DataFederation
Imports DevExpress.DataAccess.Json
' ...
Dim source = New Source("Products", jsonDataSource)

Dim query = source.
    Transform().
    UnfoldColumn("Products").
    Build("ProductsUnfolded")

Dim federation = New FederationDataSource()
federation.Queries.Add(query)

The following schema is the result of the transformation:

"CategoryID": int
"Products"
    "ProductName": string
    "UnitPrice": int