# Fields.Add

Adds a field to a data extension.

## Syntax

`Fields.Add(1)`

## Function Properties

| Ordinal | Type   | Description                                                        |
| ------- | ------ | ------------------------------------------------------------------ |
| `1`     | Object | An object that specifies the properties of a data extension field. |

The field object can contain these properties.

| Name           | Type             | Description                                                                                                                                                                                                                                                                                                                                               |
| -------------- | ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `CustomerKey`  | String           | A unique ID for the field.                                                                                                                                                                                                                                                                                                                                |
| `DefaultValue` | String or Number | The default value that’s applied to the field if one isn’t provided when a row is added to the data extension.                                                                                                                                                                                                                                            |
| `FieldType`    | String           | The type of field. Possible values: <ul><li>`Boolean`</li><li>`Date`</li><li>`Decimal`</li><li>`EmailAddress`</li><li>`Locale`</li><li>`Number`</li><li>`Phone`</li><li>`Text`</li></ul>                                                                                                                                                                  |
| `IsPrimaryKey` | Boolean          | Indicates whether the value of the field is used as a primary key. If `true`, the value is used as a primary key.                                                                                                                                                                                                                                         |
| `IsRequired`   | Boolean          | Indicates whether a value must be provided for the field when a row is added to the data extension. If the value is `true`, the data extension field is required.                                                                                                                                                                                         |
| `MaxLength`    | Integer          | The maximum number of characters that can be specified in the value of a field. For a Text field, the value must be an integer that’s greater than 0 and less than or equal to 4000, and the default value is 50. For a Decimal field, this value specifies the maximum number of digits before and after the decimal point, and the maximum value is 29. |
| `Name`         | String           | Required. The name of the field.                                                                                                                                                                                                                                                                                                                          |
| `Ordinal`      | Integer          | The position of the field in the data extension. The ordinal value is used when displaying the data extension in Contact Builder.                                                                                                                                                                                                                         |
| `Scale`        | Integer          | The number of digits that can follow the decimal point in a Decimal field. The minimum value is 0 and the maximum value is 8.                                                                                                                                                                                                                             |

For more information, see [Data Extensions Data Types in Email Studio](https://help.salesforce.com/s/articleView?id=mktg.mc_es_data_extension_data_types.htm).

## Example

This code example adds a field to an existing data extension.

```
var de = DataExtension.Init('SSJSTest');

var newField = {
  Name : "NewFieldV2",
  CustomerKey : "CustomerKey",
  FieldType : "Number",
  IsRequired: true,
  DefaultValue: "100"
};

var status = de.Fields.Add(newField);
```

For information about creating a data extension and adding fields, see [DataExtension.Add](/docs/marketing/marketing-cloud/guide/ssjs_dataExtensionAdd.md).

## See Also

- [DataExtension.Add](/docs/marketing/marketing-cloud/guide/ssjs_dataExtensionAdd.md)
- *Salesforce Help*: [Data Extensions Data Types in Email Studio](https://help.salesforce.com/s/articleView?id=mktg.mc_es_data_extension_data_types.htm)