Dataverse Tip: Showing Counts in Model-Driven Apps (It’s Easier Than It Looks)

This is not a new trick.

Not a hack.

And definitely not rocket science 🚀😄

I recently ran into this again while working on a Model-Driven app project, and I thought it’s worth sharing — because it’s one of those Dataverse things we all forget until it bites us again.

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🧩 The Everyday Scenario

You have two tables:

• Training Sessions
• Session Registrations

Each session can have many registrations.

The ask from business is very normal:

“Can we see the number of registrations directly in the Training Sessions list?”

Sounds harmless… until you switch from Canvas to Model-Driven 😅

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😎 Canvas Apps: Life Is Easy

In a Canvas app, this is a non-issue:

• Filter registrations
• CountRows(…)
• Show the value

Done. Coffee break ☕

That’s why our brain naturally goes:

“I’ll just use a Formula column in Dataverse.”

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❌ Model-Driven Reality Check

Formula (Power Fx) / Calculated columns in Dataverse:

• Work at row level
• Are great for simple logic
• ❌ Are not meant for aggregation

So counting related records in a view using a formula column… Dataverse says: “Nice try.” 😄

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✅ The Right Tool (and It’s Not Fancy)

For Model-Driven apps, the answer is simply:

👉 Rollup Columns

They are built exactly for:

• Counting related records
• Showing totals in views
• Sorting, filtering, and reporting

No hacks. No workarounds. Just using the platform as intended 👍

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🧮 Example: Registration Count (Rollup)

Step 1️⃣ Create a Rollup Column

On Training Sessions:

• Name: Registration Count
• Type: Whole Number
• Behavior: Rollup

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Step 2️⃣ Define the Rollup

• Related table: Session Registrations
• Relationship: Registration → Training Session
• Aggregate: Count
• Optional filters:

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Step 3️⃣ Add It to the View

• Open Active Training Sessions view
• Add Registration Count
• Save & publish

That’s it. No Power Fx gymnastics 🤸♂️ No late-night debugging 🌙

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⏱️ A Small but Important Detail

Rollup columns:

• Recalculate automatically in the background (usually hourly ⏳)
• Are read-only (by design)

💬 Quick tip: If you don’t see a “Recalculate Rollup” button — don’t worry. As long as the rollup exists, Dataverse will handle recalculation for you.

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🧠 The Simple Rule That Always Helps

Whenever I work with Model-Driven apps, I keep this in mind:

🧩 Formula Columns = Row-level logic 🧮 Rollup Columns = Aggregation logic

Once you remember this, Dataverse becomes much more predictable — and a lot less frustrating 😄

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🏁 Final Thought

This isn’t a new feature. It’s not complicated. It’s just one of those Dataverse basics that’s easy to overlook — especially if you spend most of your time in Canvas apps (guilty 🙋♂️).

I hit this again in my recent project, so I figured I’d share it — in case it saves someone else a few minutes (or hours).

If this sounds familiar, you’re definitely not alone 👍