# Modify values from a single row

You can use the Modify values from a single row step to build complex hierarchical data in two ways:

* You can take hierarchical data from a previous step and modify the data using incoming fields by using a series of path definitions for the single row of input.
* You can take non-hierarchical data and create a new hierarchical data structure or modify an existing hierarchical data structure and pass the structured data to other steps.

For more information, see [Hierarchical data](/pdia-data-integration/extracting-data-into-pdi/hierarchical-data.md).

### Step name

* **Step name**: Specify the unique name of the Modify values from a single row step on the canvas. You can customize the name or leave it as the default.

![Modify values from a single row step window](/spaces/YwnJ6Fexn4LZwKRHghPK/files/8B625AhhJliE3bAv5N42)

### Targets

* **Target field name**: Name of the hierarchical output field that is generated or modified using fields from a previous step.
* **Target hierarchical path**: Specify the hierarchical path inside the **Target field name** field. See [Hierarchical data path specifications](broken://spaces/YwnJ6Fexn4LZwKRHghPK/pages/ji5ygWJ7r8yORvFw3Rjj).
* **Modify action**: The action to perform on the target field.
  * **SET**: Set the target hierarchical path to the value specified in **Value field name**.
  * **SET\_IGNORE\_NULL\_VALUE**: Perform **SET** only if the value field is not null.
  * **SET\_IF\_NULL**: Set the target hierarchical path to the value specified in **Value field name** if the target path is null.
  * **UNSET**: Unset the target hierarchical path.
    * Example: `before: { hello: null, hello2: 10 }, after: {}`
  * **UNSET\_IF\_NULL**: Unset the target hierarchical path if the value stored at the path is null.
    * Example: `before: { hello: null, hello2: 10 }, after: { hello2: 10 }`
* **Value field name**: The name of the incoming field.
* **Output set path field name** (optional): The field name that contains the output path of the field that the step modified or created.

### Example

The sample transformation `Modify_From_A_Single_ROW.ktr` demonstrates the capabilities of this step and is available in the plugin distribution package in the `data-integration/plugins/hierarchical-datatype-plugin/samples/transformations` directory.

This step is also demonstrated in `Advanced_Using_Multiples_To_Join_And_Edit.ktr`. Comments in the transformations explain how the steps are used.

![Modify values from a single row example KTR](/spaces/YwnJ6Fexn4LZwKRHghPK/files/1RL1c7VGTm4FHuWdnJRB)


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