> For the complete documentation index, see [llms.txt](https://docs.pentaho.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/modify-values-from-grouped-rows/modifications-modify-values-from-grouped-rows.md).

# Modifications

| Field                 | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| --------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Hierarchical path** | Specifies the path that has to be modified or created inside the target hierarchical field. See [Hierarchical data path specifications](/pdia-data-integration/10.2-data-integration/advanced-topics-pentaho-data-integration-overview/hierarchical-data/hdt-path-specification.md)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| **Action**            | <p>Specify the action to perform on the <strong>Target field name</strong>. The modification actions you can perform with this step are:- <strong>SET</strong> – Sets the <strong>Target hierarchical path</strong> in the <strong>Target field name</strong> to the value specified in the <strong>Value field name</strong> field.</p><ul><li><strong>SET\_IGNORE\_NULL\_VALUE</strong> - Performs the <strong>SET Modify</strong> action if the value field is not null.</li><li><strong>SET\_IF\_NULL</strong> - Sets the <strong>Target hierarchical path</strong> to the value specified in the <strong>Value field name</strong> field if the target hierarchical path of the HDT is null.</li><li><strong>UNSET</strong> - Unsets the <strong>Target hierarchical path</strong> in the Target HDT <code>(before: { hello: null, hello2: 10 }, after: {} )</code></li><li><strong>UNSET\_IF\_NULL</strong> - Unsets the <strong>Target hierarchical path</strong> if the value stored at the path is null <code>(before: { hello: null, hello2: 10 }, after: { hello2: 10} )</code></li></ul> |
| **Value field name**  | Specifies the field for performing the previous action.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |


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