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fschiro's avatar
fschiro
Frequent Visitor
6 years ago
Solved

What does the dot command do [column].[column]

What does the dot "." command do in Dax?

In a quick measure I noticed 'DimDate'[Date].[Date]

I went to find documentation as to what was the purpose of the .[Date] in the [Date].[Date], but I could not find any.

Can anyone tell me what is this dot "." command [column].[column]? What does it do? Is there any documentation on it?

Thank you,
FS

  • Hi fschiro 

     

    Its a DAX reference to auto date hierarchy table that you can not see it in your model as it's hidden, normally you would use it if you do not have a date dimension.

     

    Best Regards,
    Mariusz

    If this post helps, then please consider Accepting it as the solution.

    Please feel free to connect with me.
    Mariusz Repczynski

     

6 Replies

  • In Power BI the auto date/time setting automatically creates one date table for each date column in the model.

    Columns in these auto-created tables can be accessed through “column variations”.

    'Sales'[Order Date].[Date]

     

  • Mariusz's avatar
    Mariusz
    Community Champion

    Hi fschiro 

     

    Its a DAX reference to auto date hierarchy table that you can not see it in your model as it's hidden, normally you would use it if you do not have a date dimension.

     

    Best Regards,
    Mariusz

    If this post helps, then please consider Accepting it as the solution.

    Please feel free to connect with me.
    Mariusz Repczynski

     

    • fschiro's avatar
      fschiro
      Frequent Visitor

      Mariusz 
      I'm not sure I get it. I have a date dimension, and I do see that sometimes it puts this hierarchy thing on the axis when I first select a datedimension column. But I usually have to close the hierarchy for the data to plot correctly on the date dimension column I choose.

      Is there somewhere I can read about this? What is this hierarchy thing?

  • Nathaniel_C's avatar
    Nathaniel_C
    Community Champion

    fschiro ,

    I believe the "." denotes an object that is in the class on the left side of the "." So any commands on the right side of the" . "are all grouped together as a subset of the object on the left side of the"."

     

    If this solves your issues, please mark it as the solution, so that others can find it easily. Kudos are nice too.
    Nathaniel

    • fschiro's avatar
      fschiro
      Frequent Visitor

      Nathaniel_C
      Is there any documentation on this?
      Can I create data that utilizes this? Meaning, can I create a column that contains subvalues which I can reference with dot?

      • Nathaniel_C's avatar
        Nathaniel_C
        Community Champion

        Hi fschiro , 

        I just came across this blog. At the end he says, " 

        An afterthought

        Also, please keep in mind that the dot symbol in List.Generate does not have the same meaning as in other languages either. There are no object methods in M, and there are no namespaces, so the dot is just another character without any special meaning. It could have been a dash or an underscore - it wouldn't have mattered."

         

        So unlike other languages he says it doesn't mean anything. If you find different, let us know. 

         

        If this solves your issues, please mark it as the solution, so that others can find it easily. Kudos are nice too.
        Nathaniel

        https://potyarkin.ml/posts/2017/loops-in-power-query-m-language/