Description
Yes, it’s Salesforce restriction, as Formula fields are not indexed and groupable, query will become very slow; so Salesforce does not allow group in SOQL.
SELECT count(Id) FROM Lead GROUP by Formula_Field__c
Workaround
- Create a custom field with same return type as Formula field has.
- Populate the value in this custom field using flow. This flow will be triggered on record creation/updation with Fast Field Updates.
- This flow populates the field using same formula in flow.
- Use this custom field in SOQL.