How to use Summary columns

For more explanations of what table relationships are, see this help center article.

When to use Summary columns

Use Summary columns to aggregate or summarize data from other records that are linked to your table. Summary columns provide similar summarization functionality to SUMIF(), COUNTIF(), MAX(), MIN(), SUM(), AVG() formulas in Google Sheets, but specifically for records that are linked to rows in your table.

Summary columns are great for use cases where you already have some related data linked together and you want to then report on the linked data in a table, for example:

• If you have a table of Projects and a table of Teams, where each project is linked to a team from the Teams table, you can create a Summary column in the Teams table to allow you to see all the projects that the team owns.
• You can create multiple Summary columns with different summary functions, to do things like: show the count of "Completed" projects for each team, or show the average resource cost of projects for each team.

How a Summary column works

• When creating a Summary column, you need to select an existing table relationship that is linking to your table. The relationship determines where to find the linked records to summarize data from. If you don’t have existing relationships from other tables, you will not be able to proceed. To create a new table relationship, you can create a Lookup column, or create one directly from the Relationships dialog.
• After creating the Summary column, the table column header will show the name of the source table that your summary column is reading from, and your custom column name.
• Double click or open the right-click menu on the column header to edit and rename the column, or click on "Open in Relationships dialog" to manage all summary columns for the relationship or add a relationship filter to restrict what records are summarized from the linked table (see further below).
• Multiple summary columns can be added, using the same relationship, to report on information in different ways.

Creating a Summary column

To create a Summary column, you can do this with multiple approaches:

1. Through the Relationships dialog, which you open from the "Relationships" toolbar button.
2. Through the Column settings dialog, which you open when creating a regular table column.
   1. Click the "+ Add column" button
   2. Set the custom column name
   3. Click to open the column type selector, and click on the "Link to table" > "Summary" column type.
      
      
       
   4. Click the relationship selector, where must select an existing table relationship.
      • If there are no relationships linking other tables to your table, then nothing will be shown in this relationship selector.
   5. Select the source column you want to summarize data for.
   6. Select the summary type you want to show (list the values, sum, count, etc.).
   7. Save the column configuration.

 See the second half of this YouTube video for a guided walkthrough on how to create Summary columns:

Note: the video was made with an older version of the Tables interface, but the general flow is the same.

Link tables and lookups with Tables

Filtering records in a Summary column

You can filter which rows are summarized in a Summary column, by configuring a filter for the Summary column in the Relationships dialog.

To add a Summary column filter:

1. Open the relationship in the Relationships dialog, via:
   1. Clicking on the "Relationships" toolbar button and clicking on the specific relationship
   2. Editing the Summary column and clicking on the "Open in Relationships dialog" button
2. When viewing the relationship, below each Summary column is a section where you can add filtering criteria, based on values in the linked table columns.

See the second half of this YouTube video walkthrough for using Summary column filters:

With relationship filters, now you have more control when linking data between tables