PL-300 Practice Test 7 — 10 Questions

Question 1

A user reports that a Power BI report is not refreshing data from a SQL Server database. The dataset uses Import mode. The gateway cluster shows all gateways are online. What is the most likely cause?

Accepted Answer

The data source credentials are incorrect or expired.. In Import mode, Power BI caches data and refreshes it on a schedule using stored credentials. If those credentials expire or become invalid, the refresh fails even though the gateway cluster shows as online. The gateway being online only indicates network connectivity, not that the stored credentials are still valid for the SQL Server database.

Answer

The report is using a scheduled refresh with a conflicting time.

Answer

The gateway version is incompatible with the SQL Server version.

Answer

The dataset uses DirectQuery mode which requires a live connection.

Question 2

Drag and drop the steps to create a relationship between two tables in Power BI Desktop into the correct order.

Accepted Answer

Open Model view, drag a column from one table to a column in another table, configure cardinality and cross-filter direction in the Edit Relationship dialog, then click OK.. Relationships are created by dragging columns between tables in the Model view, then confirming settings like cardinality.

Answer

Open Model view, click on the table to select it, then click on the 'Create Relationship' button in the ribbon, then select the columns from a dropdown menu, then click OK.

Answer

Open Model view, drag a column from one table to the other table header, then in the dialog that appears, choose the cardinality, then click OK.

Answer

Open Model view, configure cardinality and cross-filter direction in the Edit Relationship dialog, then drag a column from one table to a column in another table, then click OK.

Question 3

You are preparing a data model that uses a date table. You need to ensure that the date table includes all dates from January 1, 2020 to December 31, 2025. What is the most efficient way to create this date table in Power Query?

Accepted Answer

Use the 'List.Dates' function to generate the date range.. The 'List.Dates' function in Power Query M is the most efficient way to generate a contiguous range of dates directly within the query editor, without external dependencies. It creates a list of dates from a start date to an end date using a specified step (e.g., #duration(1,0,0,0) for one day), which can then be converted into a table. This approach is lightweight, fully self-contained, and avoids the overhead of importing external files or using DAX functions that are not native to Power Query.

Answer

Import a date table from an Excel file.

Answer

Use the 'Calendar' function in Power Query M.

Answer

Use the 'CALENDAR' DAX function in Power Query.

Question 4

What is the most likely cause of the error in the DAX query shown in the exhibit?

Accepted Answer

The [Sales Amount] measure is returning multiple values or is not a valid scalar measure.. The error 'A single value for column 'Sales Amount' in table 'Sales' cannot be determined' occurs because the [Sales Amount] measure is being used in a context that expects a scalar value, but the measure is defined to return multiple values (e.g., using SUMX over a table that returns multiple rows without proper aggregation). In DAX, measures used in EVALUATE statements must return a single scalar value; if the measure is not properly aggregated or contains a many-to-many relationship, it can produce multiple values, causing this error.

Answer

There is no relationship between Date and Product tables.

Answer

The SUMMARIZECOLUMNS function does not support multiple group-by columns.

Answer

The ORDER BY clause is not allowed in EVALUATE statements.

Question 5

You are modeling data from multiple sources: a SQL Server database for sales, an Excel file for budget, and a SharePoint list for product targets. You need to combine these into a single Power BI report. What is the recommended approach for handling data refresh?

Accepted Answer

Use Power Query to combine data from all sources into a single dataset, then schedule a daily refresh in the Power BI service.. Power Query (Get Data) in Power BI Desktop is designed to connect to and combine data from multiple heterogeneous sources—SQL Server, Excel, and SharePoint—into a single dataset. After publishing to the Power BI service, you can configure a scheduled refresh (via an on-premises data gateway for on-premises sources) to keep the dataset up to date automatically, which is the recommended approach for recurring refreshes.

Answer

Import each source into separate Power BI Desktop files and manually update.

Answer

Use Excel Online as the single source and import all data into it first.

Answer

Create separate datasets for each source and use composite models with DirectQuery.

Question 6

Which TWO are valid methods to handle null values in Power Query? (Choose two.)

Accepted Answer

Use the 'Fill Down' or 'Fill Up' option to propagate non-null values into null cells.. 'Fill Down' and 'Fill Up' propagate the last non-null value into adjacent null cells. Option C is correct because 'Replace Values' can replace nulls with a default value. Option B is incorrect: 'Remove Blank Rows' removes rows where all cells are blank, not rows with nulls in specific columns. Option D is not a direct method for handling nulls; merging may introduce new data but does not handle existing nulls. Option E is invalid because changing to a non-nullable type causes errors.

Answer

Remove rows that contain null values using the 'Remove Rows' > 'Remove Blank Rows' option.

Answer

Merge the table with another table that has no nulls.

Answer

Change the data type of the column to a non-nullable type.

Question 7

You are preparing data for a Power BI report. The source data contains a column 'FullName' with values like 'John Doe'. You need to split this column into 'FirstName' and 'LastName' using Power Query. The transformation should be repeatable and not dependent on the number of spaces. What is the best approach?

Accepted Answer

Use 'Split Column by Delimiter' and choose 'Right-most delimiter'.. Using 'Split Column by Delimiter' with 'Right-most delimiter' ensures that the split occurs at the last space in the FullName column, which reliably separates the first name from the last name even if there are multiple spaces (e.g., 'John Michael Doe' would yield 'John Michael' as FirstName and 'Doe' as LastName). This approach is repeatable and does not depend on a fixed number of spaces, making it robust for varying name formats.

Answer

Use 'Split Column by Number of Characters' with a fixed position.

Answer

Use 'Replace Values' to replace space with a comma.

Answer

Use 'Extract Text After Delimiter' with a space.

Question 8

You are designing a data model in Power BI that includes a fact table called 'Sales' and dimension tables 'Customer', 'Product', and 'Date'. The 'Sales' table contains columns: 'SalesID', 'CustomerID', 'ProductID', 'DateKey', 'Quantity', and 'Amount'. You need to ensure that the model follows star schema best practices and that filters from the 'Customer' table propagate correctly to the 'Sales' table. What should you do?

Accepted Answer

Create a one-to-many relationship from Customer (one side) to Sales (many side) based on CustomerID.. In a star schema, the dimension table (Customer) should have a one-to-many relationship to the fact table (Sales) based on the common key (CustomerID). This ensures that filters applied to the Customer table propagate correctly to the Sales table, maintaining referential integrity and enabling efficient query performance.

Answer

Merge the Customer and Sales tables into a single flat table.

Answer

Set the cross-filter direction to Both on the relationship between Customer and Sales.

Answer

Create a many-to-many relationship between Customer and Sales using SalesID.

Question 9

You are a data analyst at a utility company. You load a table of meter readings into Power BI Desktop from an Azure SQL Database. The table has columns MeterId, ReadingTimestamp, and Consumption. You discover duplicate rows caused by a known upstream issue where the same reading is sometimes inserted twice with identical values in all three columns. You need to remove these exact duplicate rows in Power Query while keeping one copy of each reading. What should you do?

Accepted Answer

Select all three columns, then use Remove Rows > Remove Duplicates.. Remove Duplicates treats the set of selected columns as the key for comparison. Selecting MeterId, ReadingTimestamp, and Consumption means only rows identical across all three are collapsed, which matches the described upstream duplication. Narrower keys would delete valid readings, and an index column would prevent any matches.

Answer

Add an index column, then use Remove Rows > Remove Duplicates on the index column.

Answer

Group By MeterId, ReadingTimestamp, and Consumption with an All Rows operation, then expand the first row of each group.

Answer

Select the MeterId column only, then use Remove Rows > Remove Duplicates.

Question 10

You are importing data from an Excel workbook that contains multiple sheets. You only need data from the 'Sales' sheet. In Power Query Editor, what should you do to load only that sheet?

Accepted Answer

In the Navigator dialog, select the 'Sales' sheet and click 'Transform Data'.. In Power Query Editor, the Navigator dialog allows you to preview and select specific tables or sheets from a data source before loading. By selecting the 'Sales' sheet and clicking 'Transform Data', you load only that sheet into Power Query Editor for transformation, avoiding unnecessary data. This is the correct and efficient method to import a single sheet from a multi-sheet Excel workbook.

Answer

Load all sheets, then delete the queries for sheets you don't need.

Answer

Use a filter transform to exclude rows from other sheets.

Answer

Select the entire workbook and then filter out other sheets in Power Query.