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  • Writer's pictureMichael Kolodner

Tools I Love: DLRS (the Declarative Lookup Rollup Summary tool)

Updated: Jun 16, 2023

Let me introduce you to my friend, DLRS, pronounced either “dee-el-arr-ess” or, my preference, “Dolores.”

That’s not its real name. It’s really the Declarative Lookup Rollup Summary tool. I think it’s more fun to call it Dolores because it helps me feel closer to this amazing, free, and powerful resource. DLRS was originally created by Andrew Fawcett to fill some gaps in Salesforce functionality.

🎂 DLRS is turning ten years old this month! That's something to celebrate!

DLRS gives you rollup summary superpowers that no nonprofit admin should be without.

But before I get into the superpowers, let me help you with some DLRS context, like what it means:


This is the easy part. In fact, what it really means is “this tool is for everyone, it’s easy to use.” Declarative means that something can be done with clicks, not code. So from the start, we know that DRLS is built to allow you to do things that before would have required you to write code.

(Quick side note: With the incredible growth in power of flexibility of Flow you could accomplish most of the functionality of DRLS now with Flow, which is technically a declarative tool. But that ability comes from the fact that flow has grown to straddle the declarative vs. development line. I consider it more work to build and maintain rollups via Flow than with DLRS, so I wouldn’t recommend that route. More on that below.)


Lookup refers to the fact that DLRS can perform rollup summary operations across a lookup relationship in Salesforce. This is a simple relationship between records, where one has a reference to the other. Without getting too deep into it right now, there are times when a lookup makes more sense than the tighter relationship of master detail, often known as “parent/child.”

Master detail relationships are not generally “reparentable,” usually involve cascade delete (if the parent is deleted, so are all the children), and also have implications for Salesforce record privacy (anyone that can see the parent can see the children). Standard Salesforce rollup summary fields (“RUS fields”) can only be built across a master detail relationship. DLRS allows rollups across the less-close lookup relationship.

Rollup Summary

Out-of-the-box Salesforce can make rollup summary (“RUS”) fields that show summarized information about child records, such as counting them, finding the largest (MAX) or smallest (MIN), summing, averaging, or the like. RUS fields generate some of the most interesting insights about your data, such as number of people enrolled in a program, attendance percentages, number of people in a household, etc.

OK, that’s what it means. But the most important thing to know about DLRS is that it gives you rollup summary superpowers. And those are powers you might want to focus on master detail relationships as well.

🔋 Powers DLRS Has that RUS Do Not

Whereas standard Salesforce RUS fields are limited to count, sum, mix, and max, DRLS adds quite a few operations you might want to do, including the ability to concatenate text. Two of DLRS’s powers that I think are worth calling out separately:

Relative Date Filters

One of the most common things people consider making a rollup summary about is to have a relative date filter such as “this year.” Perhaps you want to count applications “this year” or purchases “last month.” You can do that in a Salesforce report easily. And you can include relative date filters in formulas as well. But you can’t filter the records you’re going to summarize in a standard RUS field with relative date language.


Standard RUS fields can count or sum, but average is not an option. This means that the out of the box way to calculate a rollup summary average in Salesforce requires the admin to build three fields. (One to count child records, one to total the value in the child records, and the third is a formula that divides the total by the count.) Obviously this isn’t the end of the world, but DLRS allows you to accomplish an average with just one field, saving time and effort.

So even if you are dealing with rollups across master detail relationship, DLRS is a great addition to your toolbox.

Why DLRS and Not [fill in the blank]?

There are two other tools people often suggest to meet a similar need as DLRS.

Rollup Helper

Rollup Helper is a freemium AppExchange tool. Nonprofits can have up to three free rollups permanently with Rollup Helper. Also, being a commercial product, Rollup Helper has a user friendly interface and, like DLRS, it can work across lookup relationships and do more kinds of calculations. Honestly, I have nothing bad to say about RollupHelper. I just prefer to save money for nonprofits, so I’ll go with DLRS every time.


As I mentioned above, Salesforce Flow has become a very powerful tool, with most of the capabilities of code. It’s not that hard to build a record-triggered flow that loops through related records to summarize them. One major limitation here is that if you want results in realtime you will have to build at least two flows: one on create or update of a “child” record, and one on delete. As of now (and I don’t think there is any roadmap for change any time soon), record-triggered Flows can have either a create/update context or a delete context, but not both. I also think that building and testing a flow (or modifying an existing flow) each time you find a new rollup summary need is significantly more cumbersome than building a DLRS rollup.

Things You Might Want To Roll Up 🗞️

If you aren’t already brimming with ideas of things you want to roll up using DLRS or standard rollup summaries, let me try to jump start some thoughts:

If you have students applying to colleges (or high schools) you’ll probably want to know:

- How many applications does this student have?

- How many acceptances does this student have?

- How many students have applied to this school this year?

- How many applied last year?

- How many were accepted/waitlisted/rejected this year/last year?

If you rescue animals you might need to know:

- How many cats/dogs/rabbits are at each shelter?

- What is the average length of stay in shelter?

- What percentage of animals are awaiting urgent veterinary care?

If you train teachers, you might want to count:

- Enrollments in your mentorship program.

- Completed/incomplete mentorships.

- Teachers at each school that have completed your program.

If you raise money for environmental causes you might need to know:

- How many donations have gone to each nonprofit partner?

- How many unique donors have given to each partner?

If you run a women’s shelter you’ll probably need to know:

- How many times has a client been in shelter?

- What is her average length of stay?

- How many services did she access while in shelter?

This list barely scratches the surface, of course. Your own program is going to determine the fields you need. If you want even more inspiration, look at the DLRS Cookbook, which has example rollups and instructions for building them.

[Full disclosure: I helped write that cookbook.]

One More Thing To Love: DLRS is now part of Open Source Commons

Andrew Fawcett and a handful of helpers kept DLRS up to date entirely on a volunteer basis for many years. We all owe them a huge debt of gratitude! "This tool was initially a solution looking for a problem and in part a technical demonstration of the Metadata API," says Andrew Fawcett. "And wow did it ever find its place as a solution for many of its users! At its heart at the very start was a desire to continue to do what the platform does best: democratize capabilities—and that continues to make it so popular today."

In order to ensure the continued development and support of DLRS, in 2022 Andrew asked if people could step in to take over DLRS. Now it's become part of the Open Source Commons program. That means this app has a formal structure to support it, expand it, and ensure that it will forever be free for nonprofits and anyone else that wants to use it.

"Thank you everyone for your support and encouragement over the past 10 years, I cannot wait to see what it looks like in 10 more years!" - Andrew Fawcett

I’m proud to volunteer my time for the DLRS project, helping with writing and editing documentation. It’s one of the ways I try to give back to the amazing community of Salesforce professionals that have helped me so much.

Go Out and Try It!

I hope I’ve convinced you that DRLS is a tool you want in your toolbox. Be warned: as with any tool, you’re going to have to learn how to use it. (Even wielding a hammer is not as simple as just grabbing it and swinging!)

I think it’s beyond the scope of my blog to make this or a future post into a full scale How To Build Your First DLRS. But don’t worry—the DLRS documentation is extensive and the documentation team is constantly working to expand it! Need further help? Just ask in the Community Project: DLRS group on Trailblazer Community.


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