Where can you write DAX Queries apart from DAX Studio?

For Power BI, calculated table which is a Microsoft article explaining how to do this. It involves selecting new table under the modeling tab.

It is also possible to create DAX queries in excel for power pivot, though it is a less straight forward way. Also note that the DAX editor for doing the below is not the greatest.

To do this you would do the following:

1. Go to the data tab

2. Select existing connections

3.Click on the tables tab

4. Select on of your table, a screen will pop up asking how to output select table and excel will create a table

5.Right click the table, in the drop down do table --> Edit DAX.

6. In the window that opened, change the command type in the drop down to DAX

7. Write your query. Hitting on will update the table to the results of your query.

Just keep in mind that this method is better when you already have your DAX query written.

There's also a way to create DAX-Measures in MDX queries (unfortunately it doesn't work in Excel). But in case you have other client tools compatible with MDX, it's quite useful.

https://docs.microsoft.com/en-us/sql/mdx/mdx-data-definition-create-measure?view=sql-server-ver15

In addition to the other locations mentioned, you can also write DAX in SQL Server Reporting Services:

I want to use DAX in Report Builder and wasn't sure if this can be done or how to do this. Is it possible to use DAX in Report Builder?

Nowadays You can use DAX in SSAS creating calculated columns and calculated measures in OLAP cubes, in Power BI also to create new columns and measures. DAX is really powerful language used by Microsoft reporting tools.