Free Platform Developer II sample questions

Correct answer: Setting a `Database.Savepoint` before the DML operations and using `Database.rollback()` in a `catch` block.

Using `Database.Savepoint` and `Database.rollback()` provides explicit control over the transaction. By setting a savepoint before attempting the DML operations, the developer can catch any exception, roll back all changes to the state of the database before the savepoint was set, and then return a controlled error message. A simple try-catch with a thrown exception also rolls back the transaction, but using a savepoint is the canonical and most explicit way to manage partial transaction rollbacks or full rollbacks while maintaining control over the execution flow to return a specific response.

Correct answer: Expose public properties using the `@api` decorator in the JavaScript file and define them in the component's `.js-meta.xml` file.

To make LWC properties configurable in the Lightning App Builder, they must be declared as public properties using the `@api` decorator in the component's JavaScript file. Additionally, these properties must be exposed in the component's configuration file (`.js-meta.xml`) within the ` ` section. This allows administrators to set values for these properties directly in the App Builder's UI.

Correct answer: Return a `Database.QueryLocator` from a SOQL query on the `Product__c` object.

For processing large data sets (over 50,000 records), `Database.QueryLocator` is the optimal choice for the `start` method of a Batch Apex class. It bypasses the heap size limit for the total number of records retrieved by the query because it fetches records in chunks. In contrast, returning an `Iterable` or a `List ` loads all records into the heap at once, which would cause a heap limit exception with over 1 million records.

Correct answers: Enclose the callout logic within `Test.startTest()` and `Test.stopTest()` blocks.; Implement the `HttpCalloutMock` interface and use `Test.setMock` to provide a fake response.

Correct answer: Declare the List variable that holds the `Opportunity` records with the `transient` keyword.

The view state error is caused by large amounts of data being stored in the controller's properties between server requests. The `transient` keyword prevents a variable from being saved as part of the view state. While this means the data will need to be re-fetched on each postback, it directly solves the 'Maximum view state size' error by removing the large data list from the view state.

Correct answer: Use Custom Metadata Types with metadata relationships to model the data structure.

Custom Metadata Types are the best fit for this scenario. They are deployable, meaning the configuration data can be moved between environments as metadata. They can be queried using SOQL, and they support relationships, allowing the developer to model the parent-child structure between 'Service Levels' and 'Country Surcharges'. Custom Objects are data, not metadata, and are harder to deploy. Custom Settings are not as well-suited for complex relational structures and are less easily deployed.

Correct answer: Request Salesforce Support to create a custom index on the `LastLoginDate` field.

The query is timing out because it is non-selective. It has to perform a full table scan on 10 million records to find contacts where `LastLoginDate` is older than 180 days. Standard date fields like `LastLoginDate` are not indexed by default. The most effective solution is to work with Salesforce Support to create a custom index on this field. This will make the query highly selective and allow it to execute efficiently without timing out.

Correct answer: True

This statement is true. The External ID field must uniquely identify a single record for the `upsert` operation to succeed. If the value of the External ID field is not unique and matches multiple existing records, the operation will fail and a `DmlException` will be thrown, indicating that multiple records were found for the upsert.

Correct answer: `@InvocableMethod`

The `@InvocableMethod` annotation is specifically designed to expose an Apex method as a callable action in declarative tools like Process Builder, Flow, and the REST API. The method must be static and can have only one parameter, which must be a list of a primitive data type or a custom Apex class.

Correct answer: A class that implements the `Queueable` interface.

Queueable Apex is the best fit. It runs asynchronously, so it won't delay the Opportunity save. Crucially, a Queueable job can enqueue another job from within its `execute` method, which allows for complex patterns like implementing a retry mechanism. The job can maintain a `retryCount` state variable and, upon failure, re-enqueue itself if the count is below the threshold. `@future` methods cannot call other `@future` methods, and Batch Apex is overkill for a single callout.