---
title: "Add Column In Data Table Step"
url: "https://docs.robotiq.ai/en/article/add-column-in-data-table-step"
language: "en"
last_updated: "2025-12-24T15:12:25.024Z"
---

# Add Column In Data Table Step

The "Add Column In Data Table" step puts a new column into a data table you already have. Use this step to change how your data table is set up while your automation runs. You can name the new column, pick its data type, and give a default value for rows that are already there.

## How to Use Add Column In Data Table

Put a new column into a data table variable in your workflow.

### Step 1: Add the "Add Column In Data Table" Step

1.  Drag the "Add Column In Data Table" step into your workflow.

### Step 2: Set Up the Column Details

1.  In the step properties, find the **Data Table** field. Pick the data table variable where you want to add the column.
2.  In the **Column Name** field, type a name for your new column.
3.  In the **Type** field, choose what kind of data the new column will hold.

**Important:** The types of data you can use are:

-   **Integer:** For whole numbers.
-   **Decimal:** For numbers with decimal points.
-   **Boolean:** For true/false answers.
-   **String:** For text. You can set these to NULL.
-   **DateTime:** For dates and times.

### Step 3: Set Default Values for Rows That Already Exist

1.  If you picked **String** as the data type, you'll see the **Set NULL for all existing rows** option.
    -   Choose `T` (true) to make all existing rows in the new column NULL.
    -   Choose `F` (false) to set a specific value for all existing rows. This is the usual setting.
2.  If **Set NULL for all existing rows** is `F`, or if your data type isn't String, type a value in the **Value** field. This value will fill the new column for all rows that are already there.

**Important:** For all data types except String, you have to give a specific value. You can't use NULL for these types.

## What the Settings Mean

**Step name** (Optional)

-   A name you choose for this step in your process.

**Data Table** (Required)

-   The data table variable where you want to add the new column.

**Column Name** (Required)

-   The name of the new column.

**Type** (Required)

-   The kind of data the new column will hold.
-   **Example:** `String`, `Integer`, `Decimal`, `Boolean`, `DateTime`

**Set NULL for all existing rows** (Required)

-   This controls if existing rows in the new column start with NULL values.
-   You only see this option when the **Type** is `String`.
-   **T (true):** Makes existing rows NULL.
-   **F (false):** Lets you set a specific **Value**.

**Value** (Required)

-   The first value for the new column in all existing rows.
-   You must fill this field if **Set NULL for all existing rows** is `F`.
-   For all types except `String`, you have to set a value. NULL is not allowed.

## Related Articles

-   [Create New Data Table Step](https://docs.robotiq.ai/en/article/create-new-data-table-step)
-   [Delete Column In Data Table Step](https://docs.robotiq.ai/en/article/delete-column-in-data-table-step)
-   [Add Row In Data Table Step](https://docs.robotiq.ai/en/article/add-row-in-data-table-step)
-   [Update Value In Data Table Step](https://docs.robotiq.ai/en/article/update-value-in-data-table-step)

## Need Help?

Can't find what you're looking for? Join the [Robotiq Community](https://community.robotiq.ai/home/) to get help from other users and the Robotiq team.

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