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TransformationNodeBuilder.UnfoldColumn(String, String) Method

If a column is an array, transforms each element of this array to an individual record and changes the name of the column to the specified alias.

Namespace: DevExpress.DataAccess.DataFederation

Assembly: DevExpress.DataAccess.v22.2.dll

NuGet Package: DevExpress.DataAccess


public TransformationNodeBuilder UnfoldColumn(
    string columnName,
    string alias


Name Type Description
columnName String

The name of a column that should be unfolded.

alias String

A new column name.


Type Description

The result of the transformation query.


The following example demonstrates how to unfold a data source’s Products array and specify a new name for this array:

Show JSON Data
        "CategoryID": 1,
                "ProductName": "Chai",
                "UnitPrice": 18
                "ProductName": "Chang",
                "UnitPrice": 19
        "CategoryID": 2,
                "ProductName": "Ikura",
                "UnitPrice": 31
                "ProductName": "Konbu",
                "UnitPrice": 6
using DevExpress.DataAccess.DataFederation;
using DevExpress.DataAccess.Json;
// ...
var source = new Source("Products", jsonDataSource);

var query = source
    .UnfoldColumn("Products", "CategoryProducts")

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

The following schema is the result of the transformation:

"CategoryID": int
    "ProductName": string
    "UnitPrice": int
See Also