Power Query from Scratch, Part 5: Parameters, functions and a model that refreshes itself
A hardcoded folder path and a copy-pasted business rule are the same problem, and parameters plus functions are how you stop editing M code every month.
Power Query
// 32 postsTutorials, tips, and deep dives on Power Query — every post from bianca.codes tagged Power Query.
Power Query posts
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Build a star schema from a single flat file
One wide CSV, thousands of repeated names. By the end you have a fact table, two dimension tables, and a model Power BI actually wants.
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Power Query from Scratch, Part 4: Custom columns and your first look at M
Three parts of buttons, then a request that needs an 'and' the Conditional Column dialog doesn't have - time to type your first line of M.
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Power Query from Scratch, Part 3: The transforms that actually matter
Unpivot, split column and group by all look foolproof, right up until the source file adds a column or a name gets typed slightly differently than expected.
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Power Query from Scratch, Part 2: Importing and combining without the copy-paste
Files, folders, and multiple sheets go in three different ways, and the append-versus-merge decision is where most people guess wrong.
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When did the spreadsheet quietly become a database - and why that's a problem
Nobody decided to build a database out of that 80-tab workbook - it ended up doing a database's job without any of a database's guarantees.
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Power Query from Scratch, Part 1: The mental model nobody teaches you
Most people learn Power Query by clicking through wizards. Nobody explains what it's actually doing - and that gap is why queries break in confusing ways.
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The Hardest Part of Working With Messy Data Isn't the Cleaning - It's Knowing When to Stop
The mechanics of cleaning data are the straightforward part. The hard part has no function and no checklist: deciding which imperfections actually matter, and stopping there.
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3-Minute Win: Add a 'Last Refreshed' Timestamp to Any Power BI Report in 2 Minutes
The stakeholder emails asking whether the numbers are current stop the day you put the actual refresh time on the report - and a measure with NOW() is not how you do it.
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Star Schema Done Right, Part 4: Migrating a Flat Table to a Star Schema in Power BI
Power Query carves one flat sales table into a fact and three dimensions, you build the relationships, and you prove the numbers didn't move - a restructure you can't validate is just hope.
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If You've Copied the Same Power Query Steps Across Three Queries, You've Made a Mistake
Copying a query and tweaking the copy feels efficient. It isn't - three copies of the same logic is three places to update and three ways for it to drift.
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Build a Reusable Power Query Function That Cleans Any Text Column to Title Case
The same trim-and-title-case steps are copy-pasted across three of your queries - write them once as a function instead, and fix the rule in one place.
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Power Query Custom Functions: Write Once, Call From Any Query in Your Workbook
You've built the same cleanup steps in four different queries. A custom function is how you write them once and call them from all four.
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3-Minute Win: Create a Power Query Parameter to Switch Between Dev and Prod Data Sources
A query parameter holds your data source path, so switching from a test CSV to the production SharePoint file is one dropdown, not a find-and-replace through your M code.
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Build a SharePoint List-Connected Power BI Report (And Handle the 5,000-Row Problem)
Connect Power BI to a SharePoint List the way that doesn't fall over at 5,001 rows - OData filtering at the source, an indexed filter column, and a refresh schedule that doesn't need a gateway.
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Build a Dynamic Data Validation List That Updates Itself When Your Source Table Grows
You'll build a dropdown list that reads from a structured table and includes every new row automatically. No named range maintenance, no 'why isn't my new entry showing up' moments.
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What I Wish Someone Had Told Me About Working With Data in a Small Team
In a small team, you're the analyst, the engineer, the dashboard designer, and the person who explains what a p-value is at the all-hands.
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3-Minute Win: Use Power Query's 'Keep Rows Where' Filter Without Writing a Line of M
The Keep Rows filter in the Power Query UI handles 80% of row filtering tasks without you ever opening the Advanced Editor. Most people skip past it and go straight to writing M. Five clicks and you're done, and the M it generates is clean enough to modify later.
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The Skill Nobody Told You Was Half the Job: Asking Good Questions
The analysts who get traction aren't the fastest at pulling data, they're the best at unpacking what was actually being asked. The skill is asking good questions, and nobody trains for it.
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How to Say No to a Data Request Without Burning the Relationship
You can't build every dashboard that gets requested. But 'no' lands differently depending on how you say it — and most data people either say yes to everything and resent it, or say no in ways that…
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Getting Credit for Work That 'Looks Easy'
The more competent you get, the less people see the effort behind what you deliver. A clean dashboard looks effortless. A fast turnaround looks like it was always fast.
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The Difference Between a Dashboard and a Decision Tool (And Why It Matters)
Most dashboards answer the question 'what happened?' Very few answer 'what should we do?' The gap isn't data — it's intent. A dashboard built for the former often actively gets in the way of the la…
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Why Your Stakeholders Keep Asking for the Wrong Chart
They ask for a pie chart when they need a bar chart. They ask for a table when they need a trend line. This isn't ignorance — it's that they're translating a question into a visual type without kno…
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When Your Manager Doesn't Understand What You Built
You delivered a clean model, a solid dashboard, a real solution — and got a blank look in the room. The work was right. But explaining technical work to someone who doesn't share your frame of refe…
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Power Query Is Not the Right Tool for Every Data Problem
Power Query is a brilliant transformation tool. Most of the M code in production is doing things that belong in DAX, SQL, or Python - and the models are slow and the code is unmaintainable.
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Build a 'Latest Record Per Category' Query in Power Query - No Helper Columns
You'll build a reusable Power Query that finds the most recent entry per group - the kind of query that normally tempts people into messy MAXIFS workarounds in Excel. We're doing it properly, wit…
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Table.Group in Power Query: The Aggregation That Hands You Back a Table
Table.Group in Power Query returns a table of tables, unlocking complex multi-level analysis you can't get anywhere else.
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The Flow Ran Perfectly for Two Months. Then It Didn't.
You built the flow. It ran perfectly for two months. Then a colleague renamed a SharePoint column, or moved a file, or changed a dropdown value - and everything stopped. This isn't bad luck. It's…
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Avoid Bragging: Talk About Your Work Effectively
Stop cringing. There's a way to talk about your accomplishments in Excel and Power BI that sounds competent, not arrogant. It's all about framing.
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Why 'Just Learn SQL' Is the Wrong Advice for Most Excel Users
The advice is everywhere: if you're serious about data, you need SQL. But for most analysts already working in Excel and Power BI, the gap isn't SQL knowledge - it's data modelling instinct. Here…
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Nobody Knows What You Actually Do (And That's Partly Your Fault)
You deliver good work consistently, your manager knows you're reliable — and yet somehow you're invisible at promotion time. The problem isn't your output. It's that you've never made your work l…
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The state of email merge in 2026
It is 2026, and we are still stringing together premium Power Automate connectors just to avoid the Word mail merge wizard.