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Pquinlan21's avatar
Pquinlan21
Frequent Visitor
2 years ago

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Hi, I am trying to get the previous timestamp value in each column so I can calculate the change over the previous hour. I have attached a screen shot of the columns. Each row of data is pulled on an...
Pquinlan21's avatar
Pquinlan21
Frequent Visitor
2 years ago

 

Hi, this is the error I got back. Thank you for the help

  • AlexisOlson's avatar
    AlexisOlson
    Super User
    2 years ago

    Sorry, that image is too tiny to be readable. Can you share the text of the error message?

    • Pquinlan21's avatar
      Pquinlan21
      Frequent Visitor
      2 years ago

      OFFSET' Relation parameter may have duplicate rows. This is not allowed. 

      AlexisOlson 

      • AlexisOlson's avatar
        AlexisOlson
        Super User
        2 years ago

        Ah, I have seen this before.

         

        Try adding MATCHBY as explained in great detail here:
        https://pbidax.wordpress.com/2023/05/25/introducing-matchby-for-dax-window-functions/

         

        Prev_tsCST = 
SELECTCOLUMNS (
    OFFSET (
        -1,
        TableName,
        ORDERBY ( TableName[tsCST], ASC ),
        MATCHBY ( TableName[tsCST] )
    ),
    "Prev_BHCC_WQ159914B_OUT", TableName[BHCC_WQ159914B_OUT]
)

        If that column does not have unique values, then you'll need to add additional columns inside MATCHBY so their combination is something unique.