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

Introduction When beginners start using Power BI, most focus on visuals like charts and reports. However, a data professional knows that great dashboards are built on great data models. You should note that Data modelling is the foundation that determines whether your reports are fast, accurate, and scalable, or are they confusing and unreliable. In this article, we will learn about data modelling from the beginning in a way that is easy to understand. We will be covering: What SQL is and why joins exist. All SQL joins with real-life examples and syntax. Power BI relationships and how they work. The difference between joins and relationships. Fact versus dimension tables. Data modelling schemas. Role-playing dimensions and common modelling problems. Create models inside Power BI step by step. What is Data Modelling? Data modelling is the process of organising data tables so they can work together efficiently for analysis and reporting. Instead of storing everything in one massive table