Data Modeling in Power BI: Joins, Relationships, and Schemas

Introduction Data modeling is the process of organizing your data into tables, defining relationships between them, and enhancing the data with calculated fields, measures, and hierarchies. This process ensures accurate analysis and sets you up to create clear, impactful Power BI reports. Types of SQL Joins Joins are one of the most important features that SQL offers. Joins allow us to make use of the relationships we have set up between our tables. In this article, we’ll break down the core SQL join types: 1. INNER JOIN The SQL INNER JOIN statement joins two tables based on a common column and selects rows that have matching values in these columns. Example: SELECT * FROM employees INNER JOIN departments ON employees . department_id = departments . id ; In this query: employees.department_id refers to the department_id column from the employees table. departments.id refers to the id column from the departments table . The ON clause ensures that rows are matched based on these columns,