SELECTCOLUMNS or Table.SelectColumns ?

[iamprajot]

Hi

I need to create a new table using columns from existing few tables and I need to know what is the best option to go for.

SELECTCOLUMNS

or

let

    Source = Table.SelectColumns('Original Source Name',{'Column Name','Column Name2'})

in

    Source

I created a new table using first option and created a Table with 1 Unique column and than created a relationship of it with rest of the tables and than added another columns using the relationship.

Or should I go for second option in which I can create a new table from 1 existing table.

Remember, I will be later adding some complex calculated columns to this new table.

Please guide which option to go for a better model and data handling ?

[v-yuta-msft]

Hi iamprajot,

Using M code can be faster that DAX, if your data in these column is large, I recommend you to use M code because M code is more efficient than DAX in data model transforming.

Regards,

Jimmy Tao

[iamprajot]

thanks but that is a different dimension which I am not planning to explore, right now just gonna practise DAX as learning M Code is gonna consume time and also I need to add calculated columns, retrieving values from another few tables which needs hands on on M Code.
So is there any other way to do this, create a new table containing normal columns and complex calculated columns using columns from existing few tables.

[v-yuta-msft · Accepted solution]

Hi iamprajot,

Yes, you can use DAX functions like SUMMARIZE() or ADDCOLUMNS() or ( SELECTCOLUMNS(), UNION() ) to create a custom table from exsiting tables.

Regards,

Jimmy Tao

[DAXRichArd]

CANCEL REQUEST FOR HELP

I figured it out.

TEST =

DISTINCT (

SELECTCOLUMNS (

FILTER ( 'Merged Tables', [Airline Name] <> BLANK () ),

"Airline Name", 'Merged Tables'[Airline Name]

)

)

[DAXRichArd]

Hi Jimmy Tao,

Great article. Big thanks for your post.

When creating a table using your guidance above, is there a way to exclue brining in blanks?

I've successfully used the function string in the attached image and it works. But if the column I reference has blanks, PowerBI won't create the table.

I'm hoping you could provide a solution where I can exclude blanks and successfully create a table.

I've tried NOT BLANK(), NOT IS BLANK, and tried using a boolean arguement (IF), but I can't figure it out.

Thx

DAX Richard