Wenjie Fan (gggdttt) · Oct 5, 2026
@@ -0,0 +1,36 @@
+---
+bc-version: [all]
+domain: upgrade
+keywords: [contoso-demo-data-module, demo-tool, demo-data, upgrade-codeunit, preview, false-positive]
+technologies: [al]
+countries: [w1]
+application-area: [all]
+---
+
+# Contoso demo-data seeding does not need an upgrade codeunit
+
+## Description
+
+Codeunits that `implements "Contoso Demo Data Module"` (the Contoso demo-data-tool
+interface, e.g. `CreateSetupData`, `CreateMasterData`, `CreateTransactionalData`,
+`CreateHistoricalData`) are only ever invoked on demand by the demo data tool when a
+user explicitly chooses to generate or refresh Contoso demo data. They are not part of
+the extension's install/upgrade lifecycle: the platform never calls them automatically,
+and no already-provisioned tenant silently receives their records on extension
+upgrade — the user must rerun the demo tool to get new or changed Contoso records, for
+every change in that data, not just this one. Adding new seeding steps (for example a
+new reference/rate table population) inside `CreateMasterData`/`CreateSetupData` of
+such a module is consistent with every other Contoso demo-data change and does not
+leave real tenant data stale. The `upgrade-codeunit-subtype` and
+`install-code-does-not-run-on-version-upgrade` rules govern code that must run against
+real, already-provisioned tenant data; they do not apply to Contoso demo/preview data
+generation.
+
+## Best Practice
+
+Do not require `Subtype = Upgrade` wiring, `OnUpgradePerCompany`/`OnUpgradePerDatabase`
+entry points, or an upgrade codeunit for new seeding logic added to a codeunit that
+implements `"Contoso Demo Data Module"` and is only reached through
+`CreateSetupData`/`CreateMasterData`/`CreateTransactionalData`/`CreateHistoricalData`.
+Flag missing upgrade wiring only when the changed code also runs for real tenants
+outside the demo tool's on-demand generation flow.