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Lew_14's avatar
Lew_14
Frequent Visitor
4 years ago

Populate missing data using last populated row

I'm looking for some help!   I have a table that shows minute-by-minute data logs for machines in a production environment. Each row should have a 'RefNo' value however i'm finding that the last se...
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Lew_14's avatar
Lew_14
Frequent Visitor
4 years ago

I'm not sure how that would work, Tarun. Could you please explain further? I've previously added a calculated column that brings across the previous RefNo if the current RefNo is blank (using the Index, DAX below) but obviously that only works for the last populated row +1, whereas i need all unpopulated rows to be filled in with the RefNo for that particular run.

 

RefNo (amended) = if(ISBLANK('TABLE'[RefNo]),LOOKUPVALUE('TABLE'[RefNo],'TABLE'[Index],'TABLE'[Index]-1),'TABLE'[RefNo])
 
It could work by capturing the index of the last populated row of RefNo for any given run and then bring across that variable to any row where the RefNo is blank, however i'm not sure how i'd do this.
 
Many thanks
v-easonf-msft's avatar
v-easonf-msft
Community Support
4 years ago

Hi, Lew_14 

Try calculated columns as below:

Index (amended) = 
VAR a =
    CALCULATE (
        Max ( 'Table'[Index] ), 
        FILTER (
            'Table',
            'Table'[Index] <= EARLIER ( 'Table'[Index] )  
                && 
                'Table'[RefNo] <> BLANK () 
        )
    )  
RETURN
    IF ( ISBLANK ( 'Table'[RefNo] ), a, 'Table'[Index] )
RefNo2 (amended) = 
IF (
    ISBLANK ( 'TABLE'[RefNo] ),
    LOOKUPVALUE ( 'TABLE'[RefNo], 'TABLE'[Index], 'Table'[Index (amended)] ),
    'TABLE'[RefNo]
)

Best Regards,
Community Support Team _ Eason

  • Lew_14's avatar
    Lew_14
    Frequent Visitor
    4 years ago

    Hi v-easonf-msft,

     

    Thankyou for your reply, this works perfectly...almost!

     

    I mentioned that there were blank RefNo's at the start of the run and this wasn't an issue however it seems i was wrong now i've impemented your suggestion. Once the count resets to 0 i'd like the RefNo to be remain blank (as it is currently bringing across the previous RefNo and this is altering some of my visuals incorrectly), however it would be perfect if the code could look forward and grab the next available RefNo once the 'Value' count resets to 0 and the RefNo is blank, if that's possible?

     

    Many thanks,

    Lewis

    • v-easonf-msft's avatar
      v-easonf-msft
      Community Support
      4 years ago

      Hi, Lew_14 

      Not fully sure what your want. Is this the result you want?

      If so, please modify the formula of 'Index (amended)' as below:

      Index (amended) = 
VAR a =
    CALCULATE (
        MAX ( 'Table 2'[Index] ),
        FILTER (
            'Table 2',
            'Table 2'[Index] <= EARLIER ( 'Table 2'[Index] )
                && 'Table 2'[RefNo] <> BLANK ()
        )
    ) 
VAR b =
    CALCULATE (
        MIN ( 'Table 2'[Index] ),
        FILTER (
            'Table 2',
            'Table 2'[Index] >= EARLIER ( 'Table 2'[Index] )
                && 'Table 2'[RefNo] <> BLANK ()
        )
    ) 
RETURN
    IF (
        ISBLANK ( 'Table 2'[RefNo] ),
        IF ( 'Table 2'[Valuew] = 0, b, a ),
        'Table 2'[Index]
    )

      Please check 'Table 2' in my attachment.

       

      Best Regards,
      Community Support Team _ Eason
      If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

       

      • Lew_14's avatar
        Lew_14
        Frequent Visitor
        4 years ago

        Apologies, it's a little tricky to explain! Once the value resets to 0 a new count will begin for the next production run however the count can sometimes climb (to 10, for example) before the RefNo is allocated. In these cases i need the calculation to look forward and grab the next RefNo but i think your suggestion only does this where the value is 0, if i'm correct?

         

        I'm struggling to verify this as i'm receiving an error that there isn't enough available memory to add the amended index column. My table only has 20k rows and around 10 columns and i have 8GB RAM available so if there's anything you can think of to make the code more efficient that would be extremely helpful.

         

        Many thanks