Add columns through Lookup

A Lookup is an action that allows you to connect related columns between two data elements, injecting the data from one element into another. The two elements are joined by a pair of columns — one from each element — that share common values. We call these joining columns join keys.

Columns created from a lookup can be added using the Lookup function. However, you can also add a new lookup column without explicitly writing a formula. This second option is documented below.

Requirements

• To use this feature, you must have Can Edit or Can Explore access to the individual workbook.

Add a column through Lookup

Prerequisites:

• You will need at least two data elements — one to join to and one to join from
• Both elements must live in the same workbook
• Both elements must be sourced from the same connection
• The element you are joining to must not be a child of the element you are joining from

Add a Column via Lookup

Before you start: This action is only available in edit mode. To begin editing, click Edit in the top right corner of the page.

1. Select the data element that you want to add a column to.
2. Click the caret icon next to any column’s name to open its menu.
3. Select Add column via lookup.
   This will open the Add Lookup modal.
   • The first section, Which column would you like to add?, will prompt you to select:
     • A source element
     • A column, from the source element, to use in your new column
     • [optional] An aggregate value to apply to the column
   • The second section, Map two elements, will prompt you to define one or more sets of join keys.
4. Under Select element, select your source element.
   Elements are organized by their workbook pages.
5. Under Column to add, select the column you want to use in your new column.
6. [optional] Under aggregate, select an aggregate function to apply to the column’s values.
   Note: Under the hood, aggregation turns the Lookup into a Rollup.
7. Under Map two elements, select a column from each data element to use as a join key.
8. [optional] To add additional pairs of join keys, click + add another mapping and repeat step 7.