PL-300 Ep 4 Power Query Transformations | 16 Exam Questions Verified on Microsoft Learn walkthrough

Episode 4 of the MSExamLab PL-300 series: Power Query Transformations. Sixteen real exam-style questions on Merge vs Append, Unpivot, splitting columns, error handling, data profiling, and the transforms that cut load times - each answer worked through and verified against Microsoft Learn before recording. Every answer in this video was checked, question by question, against Microsoft's official documentation. No dump-site guesswork: where a bank answer is wrong, the correction is shown on screen and explained. The single most useful habit from this episode is the keyword test: if you need more columns, that is a Merge (a join); if you need more rows, that is an Append (a union). Half of the transformation questions on the exam collapse the moment you apply it. What you'll practise in this episode: Merge vs Append, and the columns-means-Merge, rows-means-Append test that settles most of them Widening a table with a join and expanding only the columns you need The correct sequence to combine two sheets into one deduplicated column: import, append, then remove duplicates Fuzzy matching to join unsanitized text that arrives with different spelling and casing Unpivot when a year or month is acting as a column heading (the classic crosstab) Split Column by Delimiter to Rows so each value lands on its own row The built-in Date transform to reduce a date to its year with no string tricks Replacing error values before setting the data type, and why Decimal not Whole Number Reading Expression.Error messages: type mismatches, and columns that were renamed or removed Data reduction that actually speeds up refresh: remove unused rows and columns, group and summarise Killing a per-row API call from a SharePoint lookup by reading lists separately and merging The IoT repeated-scenario set, where a solution must satisfy every requirement, not just one How each question works: a blank exam-style question appears with a ten-second timer, then the worked solution follows with a clear explanation of why each distractor fails. Pause whenever you need longer, and replay the answer to lock it in. Who this is for: anyone preparing for Exam PL-300: Microsoft Power BI Data Analyst, first sitting or retake. The questions mirror the real exam's style and difficulty without reproducing live items. A note on method: each answer is reconciled with the current Microsoft Learn documentation for Power BI and Microsoft Fabric at the time of recording, and the trickier items are cross-checked against the specific feature page rather than a general article. If Microsoft changes a behaviour later, comment with the question number and it will be re-verified and pinned. CHAPTERS 0:00 Intro & what you'll learn 0:52 Q1 - Merge vs Append 2:13 Q2 - Widening a table (join) 3:49 Q3 - Deduplicating two sheets 5:45 Q4 - Joining dirty text (fuzzy merge) 7:16 Q5 - Years across columns (unpivot) 8:38 Q6 - First transform on a crosstab 9:55 Q7 - One cell, many values (split to rows) 11:27 Q8 - Reducing a date to a year 12:53 Q9 - Replacing error values 14:53 Q10 - Reading a custom-column error 16:20 Q11 - A broken step reference 18:00 Q12 - Profiling and fixing a bad column 19:47 Q13 - Cutting load time 21:30 Q14 - Less data, faster report 22:59 Q15 - Killing a per-row API call 24:35 Q16 - IoT series - four solutions 26:31 Episode recap 27:14 Next episode & subscribe New episodes work through the whole PL-300 objective domain - Prepare, Model, Visualize, and Deploy - one focused set at a time. Subscribe so you catch every episode, and drop the number of any question that caught you out in the comments. Channel:    / @msexamlab   Full PL-300 playlist: open the channel Playlists tab and choose PL-300. Answers verified vs Microsoft Learn. This is exam preparation and revision practice; it is not a brain dump and does not reproduce live exam items. Tags: #PL300 #PL300Exam #PL300Prep #PL300Questions #PowerBI #PowerBIExam #MicrosoftPL300 #DataAnalystAssociate #PowerBICertification #PowerQuery #PowerQueryEditor #Transformations #MergeQueries #AppendQueries #Unpivot #SplitColumn #FuzzyMatching #ReplaceErrors #DataTypes #DataProfiling #ErrorHandling #ExpressionError #DataReduction #QueryFolding #GroupBy #SharePoint #MQuery #ETL #MicrosoftFabric #PowerBIDesktop #DataAnalytics #BusinessIntelligence #MSExamLab #ExamPrep #PowerBITutorial #MicrosoftCertification #DA100 #MicrosoftLearn #Crosstab #DateTransform #IoT #DataCleaning #ColumnProfiling #SemanticModel #LoadTime #PowerBIReports #DataSources #MSFabric #AnalystExam #CertPrep #DataModeling #SplitToRows #RemoveDuplicates #DecimalNumber #PL300Practice #PowerBIPrep #DataAnalyst #MicrosoftExam #PowerBILearning #FabricAnalytics #PowerBIExamPrep #PL300Revision #DataTransformation #MQueryLanguage #PowerBIModeling #ExamQuestions #PracticeTest #PowerBISkills #DataWrangling #CleanData #JoinTables #PivotUnpivot #ColumnSplit #DateFunctions #PerformanceTuning #DataAnalystTrain1