PL 400 Power Apps Development 3 — Questions and Answers
Question 1: Which Dataverse column type should you use to store a many-to-one relationship between a 'Contact' table and an 'Account' table?
- Lookup column (Correct answer)
- Choice column
- Text column with a business rule
- Calculated column
Correct answer: Lookup column
A Lookup column creates a many-to-one relationship by storing a reference (foreign key) to a row in a related table.
Question 2: A canvas app's gallery is bound to a collection. A user edits a row in the gallery. Which function writes those edits back to the Dataverse data source?
- SubmitForm(FormName)
- Patch(DataSource, ThisItem, {Field: Value}) (Correct answer)
- SaveData(Collection, "name")
- UpdateIf(Collection, condition, {Field: Value})
Correct answer: Patch(DataSource, ThisItem, {Field: Value})
Patch() writes a record—or a set of field updates—directly to a data source, making it the correct function for updating Dataverse from a gallery interaction.
Question 3: You are building a PCF field control. The manifest declares a property with usage='bound'. What does this mean?
- The property is linked to a Dataverse column and its value flows bidirectionally (Correct answer)
- The property is read-only configuration set by the maker
- The property fires a Power Automate flow when changed
- The property is only available at design time
Correct answer: The property is linked to a Dataverse column and its value flows bidirectionally
A bound property is connected to a Dataverse column, meaning the control reads the column's value and can write back updated values through notifyOutputChanged.
Question 4: In a model-driven app, which feature allows you to run client-side logic automatically when a form field value changes?
- JavaScript web resource registered on the field's OnChange event (Correct answer)
- Power Automate cloud flow triggered by Dataverse row update
- Business rule with condition set to 'field change'
- PCF control with updateView override
Correct answer: JavaScript web resource registered on the field's OnChange event
JavaScript web resources registered on the OnChange event of a form field execute immediately in the browser when the field value is modified.
Question 5: Which Power Apps formula would you use to combine the FirstName and LastName columns from the Contacts table into a single display string?
- Concatenate(ThisItem.FirstName, " ", ThisItem.LastName) (Correct answer)
- Merge(ThisItem.FirstName, ThisItem.LastName)
- Join([ThisItem.FirstName, ThisItem.LastName], " ")
- Text(ThisItem.FirstName & ThisItem.LastName)
Correct answer: Concatenate(ThisItem.FirstName, " ", ThisItem.LastName)
Concatenate() joins multiple text strings together, and the & operator can also be used, but Concatenate() is the explicit string-joining function.
Question 6: You need to prevent a canvas app user from submitting a form if a required email field is blank. Which approach enforces this in the app?
- Set the button's DisplayMode to DisplayMode.Disabled when IsBlank(EmailInput.Text) (Correct answer)
- Add a Power Automate flow to validate before saving
- Use a Dataverse business rule with server-side validation
- Add a required attribute to the Dataverse column only
Correct answer: Set the button's DisplayMode to DisplayMode.Disabled when IsBlank(EmailInput.Text)
Setting the submit button's DisplayMode to Disabled based on a blank-check formula prevents submission at the UI layer before any server call is made.
Question 7: Which tool in the Power Apps maker portal lets you view and resolve dependency errors before exporting a solution?
- Solution checker (with dependency analysis) (Correct answer)
- Monitor tool
- App checker in Power Apps Studio
- Environment variable editor
Correct answer: Solution checker (with dependency analysis)
The solution checker analyzes solution components for issues including missing dependencies, helping you resolve them before export or deployment.
PL 400 Power Apps Development 3
Which Dataverse column type should you use to store a many-to-one relationship between a 'Contact' table and an 'Account' table?