Teaching Data Joins: A Conceptual Approach Using SQL, Alteryx, and Tableau

The many ways of joining data can be confusing for beginning, or even intermediate, data analytics students. Several accounting information system textbooks cover SQL and joins, but few supplemental resources exist that can reinforce and clarify join concepts. In this paper, we use a multi-tool approach in a three-part assignment for teaching data joins using three different software tools. We use four different join types (INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, and FULL OUTER JOIN) in Microsoft Access, Alteryx, and Tableau. We further demonstrate how the Tableau data model, using separate logical and physical layers, implements the various join types depending on the data needs of a particular visualization. Overall, thus three-part assignment can help students develop a comprehensive understanding of joins and how to implement them in widely-used software tools. The assignment also gives students practice in selecting, using, and validating joins in data analytics.