Free PL-400 sample questions

Correct answer: Register a pre-operation step with a Pre Image alias containing the `primarycontactid` field. Access the old value from the Pre Image and the new value from the `Target` entity.

The most efficient and correct method is to use a Pre Image. By registering a Pre Image with the required attribute (`primarycontactid`), the plug-in execution context will contain a snapshot of the record *before* the update. The `Target` entity in the `InputParameters` will contain the new value being set. This avoids an extra API call to the database, making it the most performant and standard approach. Retrieving the record again in a post-operation step or querying the database in a pre-operation step introduces unnecessary overhead and potential race conditions.

Correct answer: An asynchronous post-operation plug-in that posts a message to an Azure Service Bus queue. An Azure Function listens to the queue to call the audit API.

This pattern provides the required durability and guarantee. The asynchronous plug-in will execute after the Dataverse transaction is committed. It posts a message to Azure Service Bus, which provides guaranteed delivery. A separate Azure Function can then process messages from the queue, with its own retry logic, to call the external API. This decouples the systems and ensures the audit log is eventually created even if the external API is temporarily unavailable. A synchronous plug-in would lock the UI and fail the Dataverse transaction if the API call fails. A webhook is less durable as it lacks a built-in queue for guaranteed delivery.

Correct answer: Use `context.webAPI.retrieveMultipleRecords` with a FetchXML query that links the Case entity to the Account entity.

The `context.webAPI` is the standard and supported method for performing data operations against Dataverse from within a PCF component. The `retrieveMultipleRecords` method, combined with a FetchXML or OData query, allows the component to securely and efficiently fetch related data without needing to manage authentication tokens manually. Using a direct `fetch` call is not recommended as it bypasses the component's context and security. Binding a subgrid is a configuration for forms, not a data fetching method within the component's code. Passing data via component properties is for static or parent-driven data, not for fetching related records independently.

Correct answer: The `StartsWith` function is not delegable for the `CustomerName` text column in Dataverse.

While `Filter` and equality checks on option sets (`Status = 'Active'`) are delegable to Dataverse, the `StartsWith` function on a text column is a common cause of delegation issues. Because `StartsWith` is not delegable, Power Apps first retrieves the initial 500 records (the non-delegable limit) from Dataverse that match `Status = 'Active'`, and *then* applies the `StartsWith` filter locally on that small subset. This leads to incomplete search results. The `&&` operator is delegable. To fix this, the developer should use a delegable search function like the `Search` function or filter on a different, delegable criterion.

Correct answer: Each developer exports their changes as an unmanaged solution, unpacks it into a source control repository, and merges their changes. An automated pipeline then packs the merged solution and deploys it to the build environment.

This describes a source-control-first ALM strategy, which is the best practice for team development. Each developer works in isolation. Their unmanaged solutions are unpacked (or 'decomposed') into source files. Git is used to merge the changes from different developers. A CI/CD pipeline (like Azure DevOps with Power Platform Build Tools) then automates the process of packing the merged files back into a solution and deploying it. This approach provides version history, conflict resolution, and automation.

Correct answer: Authentication type: `API Key`, Parameter label: `API Key`, Parameter name: `x-api-key`, Parameter location: `Header`

The `API Key` authentication type is specifically designed for this scenario. Configuring it with the correct parameter name (`x-api-key`) and location (`Header`) will automatically create a field on the connection creation screen, securely store the user's input, and add it as the specified header to every outbound request from the connector. This is the simplest and most secure method for handling API keys.

Correct answers: An Azure Durable Function that implements the orchestration logic.; A custom connector that invokes the Azure Durable Function.

Azure Durable Functions are designed for stateful, long-running orchestrations. They can maintain their state across system restarts and handle complex, multi-day processes reliably.

To call the Azure Durable Function from a canvas app or Power Automate, a custom connector is the standard mechanism. It provides the bridge between the Power Platform and the custom Azure-hosted logic.

Correct answer: In an `OnSave` event handler, check the date and if invalid, use `executionContext.getEventArgs().preventDefault()` and `formContext.ui.setFormNotification`.

The `OnSave` event is the correct place to perform final validation before a record is committed to the database. The `executionContext.getEventArgs().preventDefault()` method is used specifically within the `OnSave` event to cancel the save operation. After preventing the save, `formContext.ui.setFormNotification` should be used to display a clear error message to the user, explaining why the save was blocked. Placing this logic in `OnLoad` or `OnChange` would be either too early or would not prevent saving if the invalid date was already present when the form loaded.

Correct answer: True

This statement is true. The 'Pre-validation' stage is the first stage in the pipeline and occurs before the main database transaction begins. It is intended for initial validation logic. If the plug-in throws an exception here, the entire operation is aborted without initiating a transaction that would need to be rolled back. The 'Pre-operation' and 'Post-operation' stages execute within the database transaction.

Correct answer: Elastic table

Elastic tables are specifically designed for high-volume, append-heavy workloads like IoT data, logs, and telemetry. They are built on Azure Cosmos DB and offer horizontal scaling and performance benefits for handling massive datasets that standard Dataverse tables (built on Azure SQL) are not optimized for. Virtual tables are for data that resides in external systems, and standard tables are for typical business application data.