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Anonymous's avatar
Anonymous
Not applicable
5 years ago
Solved

M Query: Add list of months between dates

I'm trying to add rows for each month between two dates. I found some example code on the forums and tried to adapt it for my purposes, but it isn't working properly. I'm adding a custom column named...
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  • CNENFRNL's avatar
    CNENFRNL
    5 years ago

    Hi, Anonymous , don't bother to use List.Generate(); List.Accumulate() would come in handy in your senario. You might want to try,

    let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTLRN9Q3MjC0BDKN9Y1BbCMDpVidaCUjoIgZRNICyDRFSMYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, award_begin_date = _t, award_end_date = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", Int64.Type}, {"award_begin_date", type date}, {"award_end_date", type date}}),

    #"Added Custom" = Table.AddColumn(
        #"Changed Type",
        "col",
        each 
        let
            begin = Date.StartOfMonth([award_begin_date])
        in
            List.Accumulate(
                {0..(Date.Year([award_end_date])-Date.Year([award_begin_date]))*12+(Date.Month([award_end_date])-Date.Month([award_begin_date]))},
                {},
                (s,c) => s&{Date.AddMonths(begin,c)}
            )
    ),

    #"Expanded col" = Table.ExpandListColumn(#"Added Custom", "col")
        
in
    #"Expanded col"

Anonymous's avatar
Anonymous
Not applicable
5 years ago

It's literally just three columns:

 

ID          award_begin_date          award_end_date
1           4/1/2019                  3/31/2020
2           6/1/2018                  5/31/2020

 

I want it to expand to be:

ID          award_begin_date          award_end_date       DateRange
1           4/1/2019                  3/31/2020            4/1/2019
1           4/1/2019                  3/31/2020            5/1/2019
1           4/1/2019                  3/31/2020            6/1/2019
1           4/1/2019                  3/31/2020            7/1/2019
1           4/1/2019                  3/31/2020            8/1/2019
1           4/1/2019                  3/31/2020            9/1/2019
1           4/1/2019                  3/31/2020            10/1/2019
1           4/1/2019                  3/31/2020            11/1/2019
1           4/1/2019                  3/31/2020            12/1/2019
1           4/1/2019                  3/31/2020            1/1/2020
1           4/1/2019                  3/31/2020            2/1/2020
1           4/1/2019                  3/31/2020            3/1/2020
2           6/1/2018                  5/31/2020            6/1/2018
2           6/1/2018                  5/31/2020            7/1/2018
...

 

CNENFRNL's avatar
CNENFRNL
Community Champion
5 years ago

Hi, Anonymous , don't bother to use List.Generate(); List.Accumulate() would come in handy in your senario. You might want to try,

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTLRN9Q3MjC0BDKN9Y1BbCMDpVidaCUjoIgZRNICyDRFSMYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, award_begin_date = _t, award_end_date = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", Int64.Type}, {"award_begin_date", type date}, {"award_end_date", type date}}),

    #"Added Custom" = Table.AddColumn(
        #"Changed Type",
        "col",
        each 
        let
            begin = Date.StartOfMonth([award_begin_date])
        in
            List.Accumulate(
                {0..(Date.Year([award_end_date])-Date.Year([award_begin_date]))*12+(Date.Month([award_end_date])-Date.Month([award_begin_date]))},
                {},
                (s,c) => s&{Date.AddMonths(begin,c)}
            )
    ),

    #"Expanded col" = Table.ExpandListColumn(#"Added Custom", "col")
        
in
    #"Expanded col"

  • Anonymous's avatar
    Anonymous
    Not applicable
    5 years ago

    Brilliant! Thank you!

  • JMelo's avatar
    JMelo
    Frequent Visitor
    4 years ago

    This was great, thank you for sharing this!! 

    It also solved my problem.

    But I have this challenge to create one row for each individual day (as opposed one for for month). I'm trying to tweak the code, but it's givning me errors.

    Could you please assist? 

    Much appreciated!

     

    • crossjdesign's avatar
      crossjdesign
      Regular Visitor
      4 years ago

      JMelo  just use the List.Dates function for this, its built in to give you eactly what your lookign for, a list of all dates between a from and to date.

  • mherrerag's avatar
    mherrerag
    Regular Visitor
    2 years ago

    Life saver! Worked perfectly.

  • agusmba's avatar
    agusmba
    Advocate III
    1 year ago

    Thank you! This is exactly what I was looking for.