Is it possible to roll-up summarize child records based on a lookup field?

Question

I'm not sure whether this works or whether I'm doing something wrong so here goes: I want to have a COUNT rollup summary field that summarizes opportunity products that have a value in a lookup field. If I set the COUNT to summarize products where this field does not equal '' (ie. empty) it's always set as 0, even though one or more products do have a value in that field. Is this just a limitation of roll-up summary fields?

Answer 1

From Salesforce documentation:

You can’t use long text area, multi-select picklist, Description fields, system fields like Last Activity, cross-object formula fields, and lookup fields in the field column of roll-up summary filters.

So what you want is not natively possible in Salesforce.

You can use this workaroud.

1. Create a new field on you child object named as "Duplicate Lookup Text" of type Text

2. Create a Workflow Rule, Created and Edited to subsequently meet the criteria, and criteria being the Lookup Field is not null

3. Create a Rollup- Summary on Parent Object for Count and use the filter criteria as Duplicate Lookup Text is not null

   

Voila Done.

Src: https://help.salesforce.com/articleView?id=fields_about_roll_up_summary_fields.htm&type=5