Writing to Excel via portal submission

Although Power Pages does not natively support writing directly to Excel files, you can achieve this via Power Automate integration.

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Common Use Cases

• Exporting portal form data to Excel
• Maintaining a simple log/report for external stakeholders
• Sharing Excel sheets with teams outside Dataverse

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Implementation Steps

Flow with Power Automate (recommended way)

1. Create your Excel file:
   • Store it in OneDrive for Business or SharePoint Online.
   • Make sure it has a table defined with columns matching your expected input.
2. Create a Power Automate Flow:
   • Trigger: “When a row is added” to a Dataverse table (or “When an HTTP request is received” if calling it directly).
   • Action: “Add a row into a table” (Excel Online connector).
     • Map form fields to Excel table columns.
3. Trigger Flow from Power Pages:
   • Use a Custom Web Page + Form + JavaScript to call a Power Automate Flow via HTTP.
   • OR configure form submission logic to update a Dataverse record that in turn triggers the flow.

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Notes and Best Practices

• Ensure the Excel file is formatted as a table (Insert > Table > Name the table).
• Set appropriate permissions on SharePoint/OneDrive file.
• Use validation and throttling logic to avoid overwriting/malformed data.
• Use row ID or timestamp to uniquely log submissions.

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Example Scenario

Name	Email	Message
John Smith	john@email.com	Hello portal!

→ After submitting the portal form, this row is appended to a SharePoint-hosted Excel sheet in real time via Power Automate.