# Add Data Column

> `UiPath.Core.Activities.AddDataColumn`

`UiPath.Core.Activities.AddDataColumn`

Adds a DataColumn to a specified DataTable. [Here](https://docs.uipath.com/activities/other/latest/workflow/add-data-row-column) you can see how the **Add Data Column** activity is used in an example that incorporates multiple activities.

## Project compatibility

**Windows - Legacy** | **Windows** | **Cross-platform**

## Cross-platform Configuration

* **Column Name** - The name of the new column you want to add in the specified `DataTable` Object. This field supports only strings and `String` variables.
* **Column Type** - The type of data the added column should have. You can select it from the dropdown, the default value is `Object`.
* **To Data Table** - The `DataTable` object in which you want to add a column. This field supports only `DataTable` objects.

**Properties Panel**
* **Allow Null Values** -Specifies whether or not null values are allowed in the new column for rows that belong to the table.
* **Default value** - Specifies the default value for the new column when creating new rows. This value must match the setting in the **Column Type**.
* **Must be unique** - Specifies whether the values in each row of the new column must be unique.

## Windows, Windows - Legacy Configuration

* **Column** - A `DataColumn` object that is to be appended to the column collection of the `DataTable`. If a variable is added to this property field, all of the properties under the **Options** category are ignored. This field supports only `DataColumn` objects.
* **ColumnName** - The name of the new column you want to add in the specified `DataTable` Object. This field supports only strings and `String` variables.
* **DataTable** - The `DataTable` object in which you want to add a column. This field supports only `DataTable` objects.

**Properties**

#### **Common**

* **DisplayName** - The display name of the activity.

#### **Input**

* **Column** - A `DataColumn` object that is to be appended to the column collection of the `DataTable`. If a variable is added to this property field, all of the properties under the **Options** category are ignored. This field supports only `DataColumn` objects.
* **ColumnName** - The name of the new column you want to add in the specified `DataTable` Object. This field supports only strings and `String` variables.
* **DataTable** - The `DataTable` object in which you want to add a column. This field supports only `DataTable` objects.

#### **Misc**

* **Private** - If selected, the values of variables and arguments are no longer logged at Verbose level.
* **TypeArgument** - A drop-down list that enables you to choose what .NET datatype you want to use with the activity. The newly added column will only accept the values of the selected datatype.
  :::note
  When changing the argument type, the content of this activity is deleted.
  :::

#### **Options**

* **Allow Null Values** - Specifies whether null values are allowed in the new column for rows that belong to the table. By default, this check box is cleared.
* **Auto Increment** - Specifies if the value of the column increments automatically when a new row is added. By default, this check box is cleared.
* **DefaultValue** - Specifies the default value for the new column when creating new rows. The value must be of the type stated by the **TypeArgument** property.
* **MaxLength** - Specifies the maximum length for each row of the new column. This field supports only `Int32` variables.
* **Unique** - Specifies that the values in each row of the new column must be unique. By default, this check box is cleared.