bcquality/microsoft/knowledge/upgrade/first-install-dataversion-zero-check.md
Jesper Schulz-Wedde 2b5550c346
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Improve partner onboarding and documentation navigation (#174)
Lead with a complete plugin quick start and add task-oriented usage, troubleshooting, customization, and contribution guides. Preserve the broader plugin framing, correct conflicting contract guidance, support Agents folder reviews, and align repository validation. Convert existing sample references to clickable links without changing knowledge rules.

Co-authored-by: Jesper Schulz-Wedde <jesper.schulzwedde@microsoft.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
2026-09-09 17:31:03 +02:00

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---
bc-version: [all]
domain: upgrade
keywords: [dataversion, first-install, on-install-app-per-company, moduleinfo, zero-version]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Detect first install with `DataVersion() = Version.Create('0.0.0.0')`
## Description
On the first install of an extension on a tenant the platform records a zero data version: `AppInfo.DataVersion()` returns `Version.Create('0.0.0.0')`. During reinstall, `DataVersion()` identifies the previously installed data version. The `OnInstallAppPerCompany` trigger uses this distinction to separate a brand-new install from a reinstall. Ordinary version upgrades do not run install code.
## Best Practice
In `OnInstallAppPerCompany`, fetch the current `ModuleInfo` via `NavApp.GetCurrentModuleInfo`, compare `AppInfo.DataVersion()` to `Version.Create('0.0.0.0')`, and run first-install seed logic only when they match. On a non-zero data version, follow the reinstall path or exit.
See sample: [`first-install-dataversion-zero-check.good.al`](first-install-dataversion-zero-check.good.al).
## Anti Pattern
Treating `OnInstallAppPerCompany` as if it always implies "fresh tenant". The trigger also fires when reinstalling over an existing data set; without the `0.0.0.0` guard, first-install seed code can run again and duplicate rows.
See sample: [`first-install-dataversion-zero-check.bad.al`](first-install-dataversion-zero-check.bad.al).
## See also
- `use-upgrade-tags-not-version-checks.md` — for upgrade steps after first install, use upgrade tags rather than `DataVersion`.
- `install-code-does-not-run-on-version-upgrade.md` — ordinary version upgrades invoke upgrade code, not install code.