Forum Discussion

GiaD30's avatar
GiaD30
Helper II
2 years ago
Solved

Add missing rows with missing date and time in Power query

Hello everyone,   I need your help please.  I have a table with several IDs and for each ID, I have several dates and times and also values.  normally I should have for each IDs hourly values, bu...
Need Help
  • danextian's avatar
    danextian
    2 years ago

    Filling down should come after replacing null with something else so the replacement is included in the filldown as well.

    let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("fdBNCoAgEAXgq4hrwxnHH2jXAYL24qLaWq26f0Vhgel2+HiPN97zcZobAEQuuJUoFSgtGKoWgHX9eUTgQZRYUuseY9m9aVRJo6T0j6KvGi5lfpR7lE7K3mpb1gZrKyssKVNGb5QrI6r25QspR/nA61nhAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, #"DateTime Value" = _t, Value = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"DateTime Value", type datetime}, {"Value", Int64.Type}}, "en-US"),
    #"Replaced Value" = Table.ReplaceValue(#"Changed Type",null,"this is null",Replacer.ReplaceValue,{"Value"}),
    #"Grouped Rows" = Table.Group(#"Replaced Value", {"ID"}, {{"MinDateTime", each List.Min([DateTime Value]), type nullable datetime}, {"MaxDateTime", each List.Max([DateTime Value]), type nullable datetime}}),
    #"Added Custom" = Table.AddColumn(#"Grouped Rows", "DateTime Value", each List.DateTimes([MinDateTime], Number.Round( (Number.From([MaxDateTime])-Number.From([MinDateTime])) * 24, 0) + 1,  #duration(0,1,0,0))),
    #"Expanded DateTime Value" = Table.ExpandListColumn(#"Added Custom", "DateTime Value"),
    #"Removed Columns" = Table.RemoveColumns(#"Expanded DateTime Value",{"MinDateTime", "MaxDateTime"}),
    #"Changed Type1" = Table.TransformColumnTypes(#"Removed Columns",{{"DateTime Value", type datetime}}),
    #"Combined Original and Expanded Dates" = Table.Combine({#"Replaced Value", #"Changed Type1"}),
    #"Changed Type2" = Table.TransformColumnTypes(#"Combined Original and Expanded Dates",{{"Value", type text}}),
    #"Sorted Rows" = Table.Sort(#"Changed Type2",{{"ID", Order.Ascending}, {"DateTime Value", Order.Ascending}, {"Value", Order.Descending}}),
    #"Applied Table.Buffer" = Table.Buffer(#"Sorted Rows"),
    #"Removed Duplicates" = Table.Distinct(#"Applied Table.Buffer", {"ID","DateTime Value"}),
    #"Filled Down" = Table.FillDown(#"Removed Duplicates",{"Value"}),
    #"Replaced Value1" = Table.ReplaceValue(#"Filled Down","this is null",null,Replacer.ReplaceValue,{"Value"}),
    #"Changed Type3" = Table.TransformColumnTypes(#"Replaced Value1",{{"Value", Int64.Type}})
in
    #"Changed Type3"

     

     

     

  • GiaD30's avatar
    GiaD30
    2 years ago

    danextian  Thank you very much, it worked:)

  • danextian's avatar
    danextian
    2 years ago

    Glad it did. Could you please accept my pose as solution?

danextian's avatar
danextian
Super User
2 years ago

I checked on my code and they're not supposed to return duplicates caused I removed then in the process. You can see below that after 3 AM, 4 AM comes next and so on and so forth.

 

 

GiaD30's avatar
GiaD30
Helper II
2 years ago

danextian  You were right, it worked 🙂 thank you very much. Now, the only think that you could help me, please, instead of null on the values for the rows I add, to add the value from the latest row I have in my initial table.

  • danextian's avatar
    danextian
    Super User
    2 years ago

    I did ask what to do with the values for the added rows. If you want copy the value from the latest non-blank row before the added row, you can right click the column and select fill down. It will fill every blanks with the value of the immediately preceding non-blank row.

    • GiaD30's avatar
      GiaD30
      Helper II
      2 years ago

      danextian  Thank you very much, it works perfectly:). But I realized I missed to share one thing: my original table, before adding missing rows, has also rows where the values are null(blank). Now, when I add my missing rows, on the Values column, I need to take into consideration also the null . For example, If I have 4 rows with:

       

      Date                         Values

      6/1/2024, 1:00 AM      10

      6/1/2024, 2:00 AM       null

      6/1/2024, 4:00 AM        20

      6/1/2024, 6:00 AM        30

       

      After adding the missing time

      rows, I need to see like that:

       

      Date                                  Values
      6/1/2024, 1:00 AM.             10

      6/1/2024, 2:00 AM.              null

      6/1/2024, 3:00 AM.              null

      6/1/2024, 4:00 AM.              20

      6/1/2024, 5:00 AM.              20

      6/1/2024, 6:00 AM.              30

       

      basically, The values from the missing rows I add to be copied from the previous row I had in my original table, no matter if it s null or it has value.

       

      is there a way of doing this?

       

      Thank you again for all the help from you:)

      • danextian's avatar
        danextian
        Super User
        2 years ago

        Prior to doing anything else, I would convert the data type of that value column to text and then replace null with something like "this is null". After filling down, rows with "this is null" should stiill be preserved. I would just revert that back to null by using the same replace method and change the data type back to number.