Understanding Data Modeling in Power BI

* Introduction * Power Bi is a powerful tool that I have recently been undertaking that has challenged me and opened my eyes differently. Slowly by slowly a few things have greatly stood out to me write from the basics to a couple of advanced concepts. Before Power BI can draw a chart or a visualization, it must understand how tables relate. That structure is the data model. A strong model produces fast, accurate insights a weak model leads to wrong results. Power BI works in three layers: Power Query (clean), Data Model (relate) and Report View (visualize). Joins (Power Query) A join physically combines rows from two tables based on a shared column. In Power BI, joins live inside Power Query, accessed via Home→Merge Queries. The join type you select determines exactly which rows survive the merge. For any join: open Power Query, select your first table, go to Merge Queries→Merge as New, choose the second table, click the matching key column in each, then pick a Join Kind. Common types