MDX or DAX with using a connection to a power bi dataset

[CCCP]

HI,i would like to understand why when i create a report and using report query builder to create simple queries,  the query languages that are available are MDX /DAX when it is in import mode ,only mdx when the dataset is in direct query mode.
Is there a setting on the pbi tenant ? or it depends on the report builder version? 

thanks for your time and responses.

[v-xiaoyan-msft · Accepted solution]

Hi @CCCP ,

 MDX can be used to query data from a cube and do a pivot of that data while DAX, being more of an expression language than a query language, cannot be used similarly.

Both being expression language, MDX and DAX are designed to query an SSAS Cube. The difference, however, lies in the details. MDX can be used to query against SSAS Multi-dimensional models, while DAX is used for SSAS Tabular models. If you use Power BI for your visualization needs, it can connect to SSAS Multi-dimensional models even though Power BI primarily uses Tabular models.

DAX expressions are supported only within tabular models. You cannot use measures created by a DAX expression in a multidimensional model. A DAX query to a multidimensional model can reference a measure or other calculation that is defined in that model, but those calculations must be authored using the MDX language. DAX expressions cannot be used where an MDX expression is required and vice-versa, and some DAX functions, like PATH, are not applicable in multidimensional modeling at all.

For more you can refer to dax-vs-mdx-is-there-any-difference 

Best Regards,
Community Support Team _ Caitlyn

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