What Is DAX in Power BI?
Last Updated on November 22, 2023
Data Analysis Expressions, or DAX, refers to a formula expression language used in Power BI and Excel Power Pivot. DAX provides functions, operators, and values that are used to transform data in related tables and columns. DAX allows analysts to create custom tables, dimensions, and measurements, solve problems, and explore how two variables or data sets correspond.
Advanced PowerBI training is important for analysts or business intelligence professionals unfamiliar with DAX. It relates to complex calculations or is used to uncover patterns in unstructured datasets that might otherwise have gone undetected.
The functional language provides numeric and non-numeric functions, so it can, for example, produce visualization reports to anticipate growth percentages and split that data across jurisdictions or regions for accurate business planning.
Knowledge Requirements for DAX Users
Power BI is a machine learning-equipped platform with multiple applications and tools. Still, a baseline of understanding is essential to access data visualization and data transformation features and create reports with digital sharing options.
Users will make the best use of the tools if they grasp the formula creation process in Excel before using functions such as Count Distinct in Power BI, which calculates the number of individual, unique values within each column. However, a basic comprehension of probability, statistics, and measurement may be sufficient for some applications, along with experience working with Power BI Desktop as a starting point.
Data analysts must know how to break down statements into separate elements, what the syntax means, and be able to recreate new statements as needed. For example, if you want to create a custom formula to break down data between two columns and produce a statistically relevant new column, you will need to be able to write your own instruction with accurate syntax formatting. All these skills are covered in detail within ONLC Power BI training courses, with instructor-led, self-study on-demand, and group tuition available.
How much does Power BI cost, and is it worth investing in? Microsoft licenses start from $9.99 per month for an individual user, although Power BI Pro is also available within Microsoft 365 E5.
What Does DAX in Power BI Do?
DAX uses two different formulas or calculations to provide an end value based on the data you import or input into the platform. Calculated columns merge two columns of data into one, applying your customized filters. You can create columns through the modeling function within the application, entering formulas depending on the answers you need to find or the trends you need to identify.
The second calculation type is called calculated measures. You can create fields to aggregate data, such as ratios and percentages, again using the modeling tab and entering the appropriate formulas.
DAX doesn’t generally produce or reference individual pieces of data or specific values but applies to whole tables, columns, or fields. Users need to know how to filter that data if they want to use DAX to focus on smaller data sets or subsections.
Why Is DAX Important for Advanced Power BI Users?
Any Power BI user can create an accurate report through the platform, but DAX is necessary to perform more advanced calculations and reach a conclusion in a fraction of the time it would otherwise take. For example, if a data analyst needs to break down statistics, analyze business performance, and separate that into different products, departments, projects, or areas, a basic reporting tool would have a limited capacity.
Data fields used within standardized tables would not provide the depth of data or the filters required. Creating new measures through the DAX language means data can be manipulated to produce customized reporting and visualizations, providing bespoke insights into what the data means and how it relates to your organizational objectives.
The functions are flexible and agile. With enough knowledge of formulas, users can design inquiries based on individual rows, applying calculations to evaluate the context of the values across each row within the data table. Time intelligence functions expedite analysis projects and can add context and relevance to reporting, using date ranges, times, and periods to assess how each part of the data relates to the next.
In short, DAX simplifies complex data analytics and can carry out even extremely difficult calculations in a few clicks, working with logic and machine learning to provide the answers you are looking for from your data.
