Understanding Data Modelling in Power BI: Joins, Relationships, and Schemas Explained

I'm still fairly new to Power BI, so when the topic of data modelling came up, I won't lie — it sounded way more complicated than it turned out to be. Once I started working with an actual dataset, things began to click. For this article, I'm using a dataset of 500 Kenyan farmers tracking crops like Maize, Tea, Coffee, and Beans across counties like Meru, Kiambu, Kisumu, and Nakuru. Having something real to point at made all the difference. Here's what I learned. What is Data Modelling? Data modelling is the process of connecting different data sources, defining their relationships, and organizing them so that your Power BI visuals are accurate and make sense. Think of it as the plumbing behind your dashboard. The charts are the taps — but if the pipes are badly set up, everything that comes out will be wrong. In our Kenya crops dataset, all the information lives in one flat file — farmer names, counties, crop types, profits, everything on a single row. Data modelling is how we organiz