Free MB-820 practice test: 30 questions with answers

Table extensions add fields to existing tables without modifying the base app, which keeps upgrades safe. A copied codeunit, a report, or an unlinked page does not extend the table itself.

Page extensions add fields and actions to existing pages. Query, XMLport, and report extension objects do not extend pages.

Event subscribers attach logic to published events in the base app without modifying it. Editing the base codeunit breaks upgrades, scheduled tasks and report triggers do not hook into posting.

The IntegrationEvent attribute publishes an event for other extensions to subscribe to. Test marks test procedures, ServiceEnabled exposes procedures to web services, and EventSubscriber subscribes rather than publishes.

OnValidate triggers check values when they are entered, which enforces the rule. Comments, colours, and captions do not validate data.

Codeunits contain procedures and business logic that other objects call. Pages and reports present or output data, and queries retrieve data.

The standard APIs are the supported integration surface and remain stable across updates. Direct SQL access, emailed spreadsheets, and screen scraping are unsupported and fragile.

Job queue entries run codeunits or reports in the background on schedules, which keeps the UI responsive. Message boxes block users, index changes are unrelated, and printing does not run background processing.

API v2.0 is recommended for new integrations and custom API pages can extend the exposed entities. APIs respect permissions, are available in the online service, and do not require a separate database per entity.

Supported change notifications or webhooks deliver updates promptly, with polling as a fallback. Database scanning, manual exports, and OCR are unsupported, slow, or error-prone.

XMLports read and write XML and text files with defined structures, which suits imports. Page extensions change UI, permission sets control access, and queries retrieve data.

OAuth app registrations with service identities and scoped permissions are the supported secure approach. Shared passwords, anonymous endpoints, and personal admin logins are insecure.

Testing in a production-like sandbox and validating the upgrade path finds issues before they reach customers. Direct installs, deleting data, and removing version numbers increase risk.

Version numbers let the platform manage installation and upgrades correctly. Icons, testing, and disabled versions are not governed by the version number.

A CI/CD pipeline builds and tests automatically and publishes to a sandbox first, which gives repeatable and safer releases. Laptop builds, direct production publishing, and email installs are error-prone or unsafe.

A planned window with a verified backup reduces risk and disruption. Unplanned updates without backups, recreating environments, and peak-hour updates without notice all increase risk.

Upgrade codeunits run data migration steps when an extension installs or upgrades. Captions, footers, and permission names do not migrate data.

Backward-compatible published interfaces avoid breaking dependent extensions. Removing or renaming published items breaks dependants, and making everything private prevents deliberate extension.

Automated test codeunits with the Test attribute, run through the test toolkit, catch regressions each time code changes. Manual production checks, compile success, and user reports detect problems too late.

Sandbox environments isolate testing from production data, which protects customers. Production and live customer tenants risk data changes, and printers are unrelated.

Isolated setup and cleanup make tests reliable and independent. Using production data, random order without setup, and skipping cleanup create flaky or unsafe tests.

Assertions that the expected error occurs verify the behaviour directly. Passing without checks, visual checks, and tests that never run the code do not verify anything.

Scenario tests exercise the process across extensions, which catches integration problems. A colour review, a compile check, and an isolated unit test with no setup do not cover that process.

Code coverage shows which lines or paths are exercised, which highlights untested logic. File counts, name lengths, and comment counts do not measure test coverage.

Feature flags or setup switches enable functionality per customer without releasing separate code. Deleting features, screen resolution, and renaming do not control availability.

Enum extensions add values to existing enums without editing the base app. Indexes, captions, and backgrounds do not extend option lists.

A page extension with an action that calls codeunit logic is the supported extension approach. Editing base source, OS buttons, and new database tables are not supported UI extensions.

Report extensions add columns and data items to existing reports in a supported way. Editing base layouts, manual printing edits, and removing reports do not extend the output properly.

Permission sets with field-level permissions enforce visibility for specific users. Captions, instructions, and comments do not restrict access.

Subscribing to the published OnAfterInsert event runs logic after insertion without modifying the base code. Editing base triggers, captions, and footers do not run logic on insert.