PL-300 Practice Questions 2 — 50 Questions

Question 1

You need to create a relationship between two tables in Power BI. Both tables contain a column named 'ProductID', but the values in one table are integers and in the other are text. What should you do first?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Ensure both columns have the same data type, either by changing the data type in Power Query or in the model view.. In Power BI, relationships require matching data types on both sides of the key columns. If one 'ProductID' column is integer and the other is text, the relationship engine cannot resolve the join because the data types are incompatible. Changing both columns to the same data type—either in Power Query (recommended for performance) or in the model view—resolves this mismatch and allows a valid relationship to be created.

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Merge the two tables into one in Power Query.

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Create a new calculated column that converts the integer to text using FORMAT.

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Set the relationship to 'Many-to-many' to bypass the type mismatch.

Question 2

A data analyst creates a Power BI report using a dataset that contains sensitive salary information. The analyst needs to ensure that only HR managers can see salary columns. What should the analyst use?

Accepted Answer

Object-level security (OLS).. Object-level security (OLS) is the correct choice because it restricts access to specific tables or columns within a dataset, which is exactly what is needed to hide salary columns from everyone except HR managers. OLS is defined in the dataset's Tabular Model roles and can deny access to individual columns so that unauthorized users cannot see them in reports. Row-level security (RLS) only filters rows, not columns, so it cannot prevent viewing salary columns. Microsoft Purview sensitivity labels classify and protect data but do not control column visibility in Power BI reports, and 'Restrict access' is not a valid dataset security setting for column-level control.

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Row-level security (RLS).

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Microsoft Purview sensitivity labels.

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Set the dataset security to 'Restrict access'.

Question 3

You are preparing a Power BI dataset that will be used by report authors. The source data contains a column named 'CustomerName' with leading and trailing spaces. You need to remove these spaces in Power Query. Which transformation should you use?

Accepted Answer

Trim. The Trim transformation is specifically designed to remove leading and trailing whitespace from text values. It preserves internal spaces, ensuring names remain intact. Other transformations either target different issues or would alter the data incorrectly. Using Trim is the standard and correct way to clean this column in Power Query.

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Split Column

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Replace Values

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Clean

Question 4

You need to create a measure that calculates year-over-year growth percentage. Which DAX function should you use?

Accepted Answer

SAMEPERIODLASTYEAR. SAMEPERIODLASTYEAR is the most direct and semantically clear function for year-over-year comparisons because it returns the same period in the prior year without requiring complex interval arguments. While DATEADD('Date'[Date], -1, YEAR) produces the same result, SAMEPERIODLASTYEAR is specifically designed for this purpose and is easier to read. PARALLELPERIOD, on the other hand, shifts entire periods and may not align with the current granularity (e.g., a monthly context would return the full prior year).

Answer

DATEADD

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DATESYTD

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PARALLELPERIOD

Question 5

You are connecting to a SharePoint folder that contains Excel workbooks. Each workbook has multiple sheets. You need to combine data from a specific sheet named 'Sales' across all workbooks. Which Power Query approach should you use?

Accepted Answer

Use the SharePoint folder connector, filter by .xlsx, then expand the Content column and filter by sheet name 'Sales'.. The SharePoint folder connector retrieves all files in the folder, including Excel workbooks. By filtering for .xlsx files and then expanding the Content column, you access the binary data of each workbook. You can then filter by the 'Sales' sheet name to combine data from that specific sheet across all workbooks, which is the only approach that directly handles multiple workbooks with multiple sheets.

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Use the SharePoint Online List connector and select the document library.

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Use the Excel connector and specify the folder path.

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Use the Web connector and provide the SharePoint site URL.

Question 6

You have a Power BI model with a 'Date' table marked as a date table. You need to create a measure that calculates the running total of sales over the last 12 months. Which DAX function should you use?

Accepted Answer

DATESINPERIOD. DATESINPERIOD, is correct because it allows you to define a dynamic window of dates—specifically, the last 12 months ending with the latest date in the current filter context. When used with a measure like CALCULATE(SUM(Sales[Amount]), DATESINPERIOD('Date'[Date], MAX('Date'[Date]), -12, MONTH)), it shifts the date range backward by 12 months from the last visible date, making it ideal for a rolling 12-month total. The 'Date' table being marked as a date table ensures that time intelligence functions respect the continuous date range.

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PREVIOUSYEAR

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DATESYTD

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DATEADD

Question 7

You have a Power BI dataset that uses Import mode and refreshes daily. The source data includes a column 'LastModifiedDate'. You want to reduce the amount of data loaded during each refresh by only loading rows that have changed since the last refresh. Which feature should you configure?

Accepted Answer

Configure incremental refresh on the table using the 'LastModifiedDate' column.. Incremental refresh in Power BI allows you to filter data by a date/time column (such as 'LastModifiedDate') so that only rows that have changed since the last refresh are loaded. This reduces refresh time and data volume while still using Import mode. The feature requires a date/time column and a properly configured policy in the Power Query Editor.

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Enable query folding in Power Query.

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Use the 'Reduce data' option in Power Query Editor.

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Change the storage mode to DirectQuery.

Question 8

Refer to the exhibit. You are reviewing a Power BI data source credential configuration. The Azure Blob Storage data source uses 'Anonymous' credentials. However, the refresh fails with an error indicating that the blob container is private and requires authentication. Which change should you make?

Accepted Answer

Change credential type to 'Account Key' and provide the storage account key.. Azure Blob Storage containers that are private require authentication. The 'Account Key' credential type in Power BI uses the storage account key to authenticate via the Azure Storage REST API, which is the correct method for accessing private blob containers. Anonymous access only works when the container is configured for public access.

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Change credential type to 'Service Principal' and provide the app ID and secret.

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Change credential type to 'Basic' and provide the storage account name and key.

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Change credential type to 'Windows' for the Azure Blob datasource.

Question 9

You are reviewing a Power BI data source configuration JSON. The exhibit shows a data source definition. What is the privacy level setting for the data source 'SalesData'?

Accepted Answer

Private. The privacy level setting for the data source 'SalesData' is 'Private' because the JSON snippet shows the property "privacyLevel":"Private". In Power BI, the Private privacy level restricts data from being combined with data from other sources, ensuring that sensitive data is not inadvertently shared across queries. This setting is explicitly defined in the data source configuration and is not Organizational, None, or Public.

Answer

Organizational

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None

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Public

Question 10

You are importing data from a folder containing multiple CSV files with identical structure. You want to automatically combine all files into one table in Power Query. Which connector should you use?

Accepted Answer

Folder connector. The Folder connector is the correct choice because it is specifically designed to connect to a folder containing multiple files, and when combined with the 'Combine Files' transformation in Power Query, it automatically merges all CSV files with identical structures into a single table. This connector handles the iterative process of reading each file and appending rows without manual scripting.

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Excel Workbook connector

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CSV connector

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Web connector

Question 11

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.

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

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The gateway version is incompatible with the SQL Server version.

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The dataset uses DirectQuery mode which requires a live connection.

Question 12

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.

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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.

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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.

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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 13

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.

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Use the 'Calendar' function in Power Query M.

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Use the 'CALENDAR' DAX function in Power Query.

Question 14

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.

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There is no relationship between Date and Product tables.

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

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The ORDER BY clause is not allowed in EVALUATE statements.

Question 15

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.

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

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

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

Question 16

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.

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Merge the table with another table that has no nulls.

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

Question 17

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.

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

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Use 'Extract Text After Delimiter' with a space.

Question 18

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.

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

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

Question 19

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.

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

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

Question 20

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.

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

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Use a filter transform to exclude rows from other sheets.

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