M language or DAX While data loading

[BalaVenuGopal]

Hi All ,

Could you plese suggest.

While loading my data to powerBi model assume i need to perform some trasnfromations like selft join and inner join we can do the same thing by using M query and Dax also

So which way we need to choose. Please suggest with explanaiton.

Thanks for your effro in advance.

[v-yuta-msft · Accepted solution]

Hi BalaVenuGopal,

If your report only visualize data from the table after perform join action or you import large amount of data from data source, it is preferable to use power query because the performance in power query will be better than DAX. Click Query Editor -> Merge Queries -> Select Join Kind.

If you need to visualize data both from table before and after perform join action, or import small data from source table, you can use Power Query or DAX formula  such as GENERATEALL and CALCULATETABLE to create a calculated table. Please refer to this case:

https://community.powerbi.com/t5/Desktop/left-outer-join-using-dax-Multiple-to-Multiple/m-p/225206

Best Regards,

Jimmy Tao