Question 18

Explanation

Rollup fields perform calculations on values that are stored in a field in a related entity across a one-to-many relationship. Rollup fields can calculate sum, min, max, and count values in a fashion that is similar to how these same functions are used within Microsoft Excel. Rollup fields are read-only and can calculate values based on a system account with full access to all records in a related entity, so they might calculate values based on records that a current user cannot access due to security settings that prevent the user from access.

Rollup fields are calculated by Microsoft Dataverse and the value of the rollup calculation is stored within the field in the entity, meaning that rollup fields can be used for sorting, searching, and filtering like any other field.

Rollup calculations are calculated asynchronously (meaning not in real-time) by using a scheduled system job in Dataverse. Rollup calculations run once an hour by default, but you can schedule them to run as often as needed by accessing Settings → Customizations → Customize the System → Components → Entities in the Solution Explorer window, and updating the settings for when the rollup occurs.

Creating a rollup field is a simple process, but you should consider the following points before you begin.

You must create a supported field type in an entity and then define the rollup that you want to calculate. The following field types support rollups:

• Whole Number

• Decimal Number

• Currency

• Date Time

The key considerations about rollups are as follows:

• When you specify the field and select a supported field type, you can define the rollup calculation.

• Rollups calculate a value from a field in one or many child records in a related entity.

• You are limited to a maximum of ten (10) rollups for each parent entity.

• Rollup fields are read-only.

• Because rollup attributes persist in the database, they can be used for filtering or sorting just like regular attributes.

• Remember that rollups are asynchronous and are calculated by Common Data Service on a set schedule, so you might not see the expected value in a rollup until that job runs.

Follow these steps to create a rollup calculation:

1. Open PowerApps.

2. Expand Data → Entities.

3. Select the entity that you want, select Fields, and then select Add Field.

4. Provide the required information for the field, including the Display name, Name, and Data type.

5. Select Add → Rollup.

   
   

   Note: You must define a relationship of one from this entity to many for another entity or the ability to define a rollup will not be available.

   
   

6. Define the rollup calculation by using the following guidance.

7. In the Source entity section, specify the entity for which the rollup field is defined and whether you will aggregate over a hierarchy or not. You can add filters with multiple conditions to specify the records in the hierarchy that you want to use for rollup.

8. In the Related entity section, you can specify that you want to calculate a rollup value from records in the related entity that are directly related to the current parent record by selecting Yes for the Hierarchy option. This specification means that the calculation is performed by using values in the child records, or you can create a rollup of all records in a related entity by selecting No in the hierarchy.

9. You can add filters with multiple conditions to specify which related records to use in the calculation. For example, you can include the revenue from the open opportunities with annual revenue that is greater than $1000 US dollars.

10. In the Aggregate section, specify the metric that you want to compute. You can choose available aggregate functions, such as SUM, COUNT, MIN, MAX, or AVG.

11. Save the new field and entity that is holding the rollup.

The rollup is now ready to use. It will run and recalculate based on the schedule that you set regardless of which form that you use to access the data that is associated with this rollup.