DAX Reference

Overview
Learning a new language can be over-whelming. Within the Data Analysis eXpression (DAX) language there are many different commands. However it is quite possible to create a professional Power BI solution using a small sub set of the commands available. Where this small sub set of DAX commands together have a much more manageable learning experience.
There are two types of best practice to keep the usage of DAX as simple as possible …
•         Aim for your data model to be a star schema.
•         Perform as much transformation within the data load process as possible, either in Power Query (for Power BI) or SSIS for Analysis Services Tabular Model.
If you follow the above best practices in full you will be very pleased as to how many insightful and attractive data visualisations you can easily create within a very short period of time.
The examples are included within the sample AdventureWorks PowerPivot and AdventureWorks PowerBI solutions so you can gain a greater context of the example code against each function description. Please click on the following link to examine these data models.
There is also a DAX query script where some example code is executed within the context of a DAX query as instead of a column or measure within a model. Please download DAX Studio https://daxstudio.codeplex.com/ to view / analyse and run the DAX query scripts.