In this video, we will continue learning more about DAX and will build a few basic functions.

Name of a Measure =SUM (Table Name [Column Name in the Table])

The above formula equals to the sum of a column in a table. For example, it could be the measure named Total Quantity, which equals to the sum of the column Quantity in a sales table.

Every DAX formula starts with the equal sign (=), similar to an Excel formula, followed by a function name, such as SUM, COUNT, AVERAGE and etc.

After the function, a table’s name is referenced and then finally a column. You must add the table name when using a column from a different table. It is important that table names are unique in the database.

The intelligent autofill function is quite helpful when choosing between tables and columns, one has to simply press the TAB key to select a right choice.

### Should I learn all DAX functions to use Power BI?

There are over 200 DAX functions and operators in Power BI. However, have no fear, because knowing around 30 functions should be good enough. In most cases, these basic functions are enough to build calculations for most reports, especially as a business user.

One could divide DAX functions into five major categories – math & statistics, logical, text, filter, and date & time functions.

Most of these functions will look familiar to Excel users. Even if they are written differently in DAX, their logic they are same. That is why, Excel users should grasp DAX pretty quickly.