Forum Discussion

greenawayr's avatar
greenawayr
Helper I
6 years ago
Solved

Variance between rows if multiple entries exist in specified timeframe

Hi,   Fairly new to PowerBI here so sorry if this is something that should be straightforward.   I have a parent table that has Unique ID for each row.   I have a child table that gets written ...
Need Help
  • Anonymous's avatar
    Anonymous
    6 years ago

    Hi greenawayr,

    In fact, I already filter on the 'parent' field to find out the minimum date based on its 'id' and stored into a variable.
    After these steps, you can use current id and the first date to lookup the correspond score and calculate with the current score to get the diff.

    Diff =
VAR currScore =
    MAX ( LIVE[Score] )
VAR currID =
    MAX ( LIVE[ID] )
VAR currDate =
    MAX ( LIVE[Modified] )
VAR prevDate =
    CALCULATE (
        MIN ( Staging[Modified] ),
        FILTER (
            ALLSELECTED ( Staging ),
            [ParentID] = currID
                && [Modified] <= currDate - 30
        )
    )
VAR prevScore =
    LOOKUPVALUE (
        Staging[Score],
        Staging[ParentID], currID,
        Staging[Modified], prevDate
    )
RETURN
    IF ( prevDate <> BLANK (), currScore - prevScore, 0 )

    BTW, My formula is a measure, please not use it in a calculated column.

    Regards,

    Xiaoxin Sheng

greenawayr's avatar
greenawayr
Helper I
6 years ago

Thanks,

 

So I'm dealing with a "LIVE" table and a "Staging" table. So the schemas are much the same, but the live table only holds one row per record and the staging table holds a record for each modifcation made to the parent record.

 

So LIVE

IDMODIFIEDScore
101/22/202015
201/22/20208
301/20/202012

 

and Staging

RowIDParentIDModifiedScore
6201/22/20208
5101/22/202015
4301/20/202012
3201/10/202012
2212/20/201911
1112/05/201913

 

So for the LIVE table, ID 2, it's current score is 8, but 30 days ago it was 11 (we ignore the score change that made it 12, we just want the score as it was 30 days ago) and the variance is -3.

 

Hope this helps. Thanks

Anonymous's avatar
Anonymous
Not applicable
6 years ago

Hi greenawayr,

You can try to use the following measure formula to get the diff between the current 'live' score and filtered first 'staging' score based on 'ID' group:

Diff =
VAR currScore =
    MAX ( LIVE[Score] )
VAR currID =
    MAX ( LIVE[ID] )
VAR currDate =
    MAX ( LIVE[Modified] )
VAR prevDate =
    CALCULATE (
        MIN ( Staging[Modified] ),
        FILTER ( ALLSELECTED ( Staging ), [ParentID] = currID )
    )
VAR prevScore =
    LOOKUPVALUE (
        Staging[Score],
        Staging[ParentID], currID,
        Staging[Modified], prevDate
    )
RETURN
    currScore - prevScore

Regards,

Xiaoxin Sheng

  • greenawayr's avatar
    greenawayr
    Helper I
    6 years ago

    Sorry, I'm not having much luck with this, I may not be explaining it properly.

     

    My Staging table could contain multiple rows child rows and therefore I need a way to return the current score, only for the first row that matches my Parent ID, is older than 30 days and sorted in ascending order.

     

    I've created a column that calculates the number of days between todays date and the modified date, and gives me an integer, so in theory I'm looking for the score where ID = Parent and && CalculatedModifiedDate > 30. However, because this returns more than one value, I'm getting errors around returning multiple results in a scalar value. I've TopN, Min etc, but keep seeming to get the same error.

     

    How do I get only one result returned so I can store that in a column and subtract it from my LIVE score?

    Thanks for your help so far.

    • Anonymous's avatar
      Anonymous
      Not applicable
      6 years ago

      Hi greenawayr,

      In fact, I already filter on the 'parent' field to find out the minimum date based on its 'id' and stored into a variable.
      After these steps, you can use current id and the first date to lookup the correspond score and calculate with the current score to get the diff.

      Diff =
VAR currScore =
    MAX ( LIVE[Score] )
VAR currID =
    MAX ( LIVE[ID] )
VAR currDate =
    MAX ( LIVE[Modified] )
VAR prevDate =
    CALCULATE (
        MIN ( Staging[Modified] ),
        FILTER (
            ALLSELECTED ( Staging ),
            [ParentID] = currID
                && [Modified] <= currDate - 30
        )
    )
VAR prevScore =
    LOOKUPVALUE (
        Staging[Score],
        Staging[ParentID], currID,
        Staging[Modified], prevDate
    )
RETURN
    IF ( prevDate <> BLANK (), currScore - prevScore, 0 )

      BTW, My formula is a measure, please not use it in a calculated column.

      Regards,

      Xiaoxin Sheng

      • greenawayr's avatar
        greenawayr
        Helper I
        6 years ago

        Hi,

         

        Sorry, I marked this as the correct answer by mistake.

        I think the problem here is the solution given is a measure.

         

        I need to see the variance from the "Current Score" in Live, to the Current Score of the child item in the staging table that is the Max modified date but older than 30 days.

         I'm trying the below, which seems to be performing the correct calculation as there are Variances being shown where they exist, however it's not pulling back the correct variance as I can see calculations happening which include values that weren't last score 30 days ago.

        ColScoreDiff = 
VAR prevDate = CALCULATE(MAX(Risks_Staging[Modified]),FILTER(ALLSELECTED(Risks_Staging),Risks_Staging[iHubRef]=Risks_LIVE[iHubRef] && Risks_Staging[Modified] <= TODAY() - 30))
VAR prevScore = LOOKUPVALUE(Risks_Staging[CurrScore],Risks_Staging[iHubRef],Risks_LIVE[iHubRef],Risks_Staging[Modified], prevDate)
Return
IF(prevDate<> BLANK (), Risks_LIVE[CurrScore] - prevScore, 0)

         

        0123217/12/201916
        0123202/11/20194

         

        And in my parent table I would have

        IDScoreVariance
        01232168

        In this case I wouldn't expect to see a variance as the Live score is the same as the score 30 days ago. However, in my DAX shown above it returns a value of -8, which shows that I'm looking up a value at least, but not quite with the correct parameters and I cannot figure out why.

         

        Thanks again