# Set Field Value to a Constant

The Set Field Value to a Constant step replaces the value of a field with a constant value you define.

### General

| Field                        | Description                                                                                               |
| ---------------------------- | --------------------------------------------------------------------------------------------------------- |
| **Step name**                | Specify the unique name of the step on the canvas. You can customize the name or leave it as the default. |
| **Use variable in constant** | Select to substitute variables inside the constant value.                                                 |

### Fields

![Set Field Value to a Constant](https://773338310-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FYwnJ6Fexn4LZwKRHghPK%2Fuploads%2Fgit-blob-7690e961f3f3f91b1abd70c71039e55728af4776%2FPDI_SetFieldValueConstant_Options.png?alt=media)

Use the **Fields** table to define the fields to replace.

Select **Get fields** to populate the table with fields from the incoming stream.

| Column                     | Description                                                                                                                                                                          |
| -------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Field**                  | Field whose value is replaced.                                                                                                                                                       |
| **Replace by value**       | Constant value used as the replacement.                                                                                                                                              |
| **Conversion mask (Date)** | Date format to use when the target field is a date. See [Common Formats](https://docs.pentaho.com/pdia-data-integration/pdi-transformation-steps-reference-overview/common-formats). |
| **Set empty string?**      | Set to `Y` to output an empty string when the replacement value is empty. If `N`, an empty value becomes null.                                                                       |

### Metadata injection support

All fields of this step support metadata injection. You can use this step with [ETL metadata injection](https://docs.pentaho.com/pdia-data-integration/pdi-transformation-steps-reference-overview/etl-metadata-injection) to pass metadata to your transformation at runtime.