---
title: Row Number Custom Value
slug: segment/row-number-custom-value
docTags: 
createdAt: 2026-01-15T20:26:39.360Z
---

:::hint{type="info"}
This feature is available on **Unaric Segment Plus **and **Advanced**.
:::

Row Number Custom Value (that is translated as* ROW\_NUMBER() *in SQL) allows you to create sequential numbers (eg. 1,2,3..) on each row of a Data Extension. The use of ascending (ASC) and descending (DESC) are also supported on this Custom Value.

:::hint{type="success"}
To learn how to use this Custom Value to combine Customers and Vouchers Data Extensions to randomly match one voucher to a customer, see [Combine Data Extensions without Matching Columns](docId:4hmWOEmIvBZMkC5ilC22r).
:::

## Video overview

::embed[]{url="https://vimeo.com/681368661?fl=pl&fe=vl"}

## Create a Row Number Custom Value

1. Under **Custom Values**, click the **Add new value** button.
2. Provide a name for the Custom Value, select *Apply formula to a field* as **Type**, and click **Next.** 

::Image[]{src="https://support.deselect.com/hc/article_attachments/29506931198097" size="50" width="1326" height="1352" isUploading="false" darkWidth="1326" darkHeight="1352" showCaption="false"}

3. Select *Row Number *as **Type of Formula **and click **Next.**

::Image[]{src="https://support.deselect.com/hc/article_attachments/29506931202833" size="50" width="1330" height="1358" isUploading="false" darkWidth="1330" darkHeight="1358" showCaption="false"}

4. Select the **Data Extension**, **Field**, and either *ascending* or *descending* **Order** to start the subsequent numbering, e.g., in the case below, the numbering will start from the lowest **CustomerId.**

::Image[]{src="https://support.deselect.com/hc/article_attachments/29506931204369" size="60" width="1324" height="1348" isUploading="false" darkWidth="1324" darkHeight="1348" showCaption="false"}

5. Click **Save** and move the new Custom Value to the Target Data Extension fields.