Extract to Rows
You can use the Extract to row step to parse hierarchical data type fields coming from a previous step and put it into the PDI stream. This step supports wildcards for arrays and for string keys. After parsing the data, a data type is assigned to the data. See Hierarchical data for an overview of hierarchical data in Pentaho.
Options
The Extract to rows step has the following options:
| Option | Description |
| Step name | Specifies the unique name of the Extract to rows step on the canvas. You can customize the name or leave it as the default. |
| Source hierarchical field | Specifies the hierarchical input field name from the previous step, which will be used to extract the data. |
| Pass through fields | Select to add the input fields to the output fields. |
Fields
| Field | Description |
| Hierarchical data path | Complete path of the field name in the hierarchical field source. |
| Output field name | Name of the field that maps to the corresponding field in the hierarchical input source. |
| Type | Data type of the generated output field. |
| Path field name | (Optional) Adds the hierarchical path as a new output field with the specified name. |
Fields
| Field | Description |
| Hierarchical data path | Complete path of the field name in the hierarchical field source. See Hierarchical data path specifications |
| Output field name | Name of the field that maps to the corresponding field in the hierarchical input source. |
| Type | Data type of the generated output field. |
| Path field name | (Optional) Adds the hierarchical path as a new output field. |
Example
The sample transformation Advanced_Using_Multiples_To_Join_And_Edit.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. Comments in the transformation explain how the steps are used. 