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ck_ky's avatar
ck_ky
New Member
4 months ago
Solved

Create measure to return value from column when condition met for two other columns

I am new to PowerBI. I am trying to return the minimum air temperature based upon the date and county that the minimum soil surface temperature is identified thru the VAR function.   Each county i...
  • v-sgandrathi's avatar
    4 months ago

    Hi ck_ky,

     

    If your measure is returning BLANK, it's often because the filter context isn't finding an exact row match between the two tables. Since your soil data is recorded every 5 minutes and the air data is hourly, the Date/Time fields likely don't line up perfectly.

    Here are a few things to check:

    1. Ensure both tables use the same Date column datatype and format.
      • One table might have full DateTime values, while the other only has Dates.
      • Even a hidden time component can prevent a match.
    2. Try matching only on the Date part, not the full DateTime.
    3. Confirm that county names match exactly in both tables.
      • Extra spaces or differences in capitalization can also result in BLANK values.

    You can test with a simplified formula like this:

    Min Daily Air Temp =
    VAR _MinSoil =
        MIN ( 'Soil.Temp'[Soil Surface Temperature (F)] )

    VAR _Date =
        CALCULATE (
            MIN ( 'Soil.Temp'[Date] ),
            FILTER (
                'Soil.Temp',
                'Soil.Temp'[Soil Surface Temperature (F)] = _MinSoil
            )
        )

    VAR _County =
        CALCULATE (
            SELECTEDVALUE ( 'Soil.Temp'[County Name only] ),
            FILTER (
                'Soil.Temp',
                'Soil.Temp'[Soil Surface Temperature (F)] = _MinSoil
            )
        )

    RETURN
    CALCULATE (
        MIN ( 'NASA Power Weather Data'[MinTempF] ),
        FILTER (
            'NASA Power Weather Data',
            'NASA Power Weather Data'[County Name only] = _County
                && DATEVALUE ( 'NASA Power Weather Data'[Date] ) = DATEVALUE ( _Date )
        )
    )

    If you still get BLANK, try creating a temporary table visual displaying:

    • Soil Temp Date
    • Air Temp Date
    • County from both tables
    • The calculated variables

    This can help pinpoint which field isn't matching between the tables.

     

    Thank you.