The answer is to use Table.ColumnsOfType to filter common columns. This function is correct because it dynamically identifies and retains only the columns that share a consistent data type across all tables, effectively isolating the common columns when combining Excel files with Power Query. On the Microsoft Power BI Data Analyst PL-300 exam, this question tests your ability to handle schema inconsistencies in data ingestion scenarios, such as when files in a SharePoint folder have extra columns that should be excluded. A common trap is choosing Table.Combine, which naively appends all columns and introduces nulls for missing ones, or Remove Other Columns, which requires you to manually know which columns are common beforehand. Remember the memory tip: “ColumnsOfType finds the intersection, Table.Combine just adds the collection.” This ensures your combined dataset stays clean and aligned with the requirement to include only columns present in every source file.
PL-300 Prepare the data Practice Question
This PL-300 practice question tests your understanding of prepare the data. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
You are using Power Query to combine data from multiple Excel files in a SharePoint folder. Each file has a sheet named 'Sales'. The columns across files are identical but occasionally a file has extra columns. You need to ensure the combined table contains only the common columns across all files. Which Power Query step should you use?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use Table.ColumnsOfType to filter common columns
Option D is correct because Table.ColumnsOfType allows selecting only columns that appear in all tables. Option A is wrong because Table.Combine appends all columns, creating nulls for missing columns. Option B is wrong because Merge queries are for joining, not combining. Option C is wrong because Remove Other Columns removes columns not selected; you need to identify common ones first.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Use Table.Combine with the 'Table1' parameter
Why it's wrong here
This combines all columns, not only common ones.
✗
Use Remove Other Columns on the first file's columns
Why it's wrong here
This would remove columns not in the first file, but other files might have fewer columns.
✓
Use Table.ColumnsOfType to filter common columns
Why this is correct
Table.ColumnsOfType returns columns that exist in all tables.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use Merge Queries as New
Why it's wrong here
Merge is for joining tables by key, not appending.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which PL-300 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Prepare the data — This question tests Prepare the data — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use Table.ColumnsOfType to filter common columns — Option D is correct because Table.ColumnsOfType allows selecting only columns that appear in all tables. Option A is wrong because Table.Combine appends all columns, creating nulls for missing columns. Option B is wrong because Merge queries are for joining, not combining. Option C is wrong because Remove Other Columns removes columns not selected; you need to identify common ones first.
What should I do if I get this PL-300 question wrong?
Identify which PL-300 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This PL-300 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PL-300 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.