Forum Discussion

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...
Need Help
  • 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"

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.