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manoolya's avatar
manoolya
Copper Contributor
Oct 13, 2022
Solved

How to delete cells in one column expect the first one based on another column

Hi

below is a sample of my data:

 https://www8.0zz0.com/2022/10/13/03/289351819.png

For each city (example ABHA and AL HASA) for each day i want to delete the redundant day

only keep the day with first entry of column time 

 

I tried delete duplicate for column date, its woks but it also deletes the rest

4 Replies

    • manoolya's avatar
      manoolya
      Copper Contributor

        

      Thank you again for introducing me to the power query. I appreciate your help

       

      I tried:

       Group By [station_name] & [observation_date], aggregation = Max of [observation_time]

      and it works well

      https://www11.0zz0.com/2022/10/14/11/611227551.png 

       

      But when I add the rest of column, it did not summarize the result 

       Group By [station_name] & [observation_date] & [latitude] & [longitude] & [wind_direction_angle] & [wind_speed_rate] &[sky_ceiling_height] & [visibility_distance] & [air_temperature] & [air_temperature_dew_point] &[atmospheric_sea_level_pressure] , aggregation = Max of [observation_time]

       

      https://www11.0zz0.com/2022/10/14/11/427881256.png 

       

      https://www11.0zz0.com/2022/10/14/11/209723794.png  

       

       

      https://files.fm/u/3tktf8t66

       

      Lorenzo

      • Lorenzo's avatar
        Lorenzo
        Silver Contributor

        Hi manoolya 

         

        (I don't have WinRar and won't install it). Quickly looking at your pictures and what you explain it seems the Grouping to to granular

         

        In the attached file, a different approach for 2 scenarios:

        - Your data are Sorted DESC on [observation_time] (as shown in your initial picture) => FirstRecordDataSorted

        - Your data are not sorted => FirstRecordDataNotSorted

         

        In both cases we Group By [station_name] & [observation_date2] only. Then inside each group we keep the 1st record only when data are sorted OR Sort [observation_time] DESC then keep the 1st record only when the data were not sorted. After that we combine the nested tables

         

        Hope this helps & makes sense

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