Sum the value of the next 4 dates with the same brand value

[haoqizha]

Hi,

I have got a sample table like below where it is by week, by retailer and by brand, with its QTY.

I now need to create a New column from Query by M, so that it sums the QTY from the "next" 4 dates with the same Retailer and Brand. (So in the below example, the first value of this column is 10 + 6 + 3 +10 = 29, that is the sum of the next 4 dates of QTY from Retailer X and Brand A).

Date	Retailer	Brand	QTY	New column (Sum QTY of next 4 dates)
01/01/2023	X	A	10	29
01/01/2023	Y	A	5
01/02/2023	X	A	6
01/02/2023	Y	A	2
01/03/2023	X	A	3
01/03/2023	Y	B	5
01/04/2023	X	A	10
01/04/2023	Y	B	20
01/04/2023	Y	B	15

I have tried List.Sum and FirstN but cannot eventually get it right. Any help please!

[v-cgao-msft]

Hi @haoqizha ,

Please check: Is this the output you expected?

Advanced editor:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMtQ31DcyMDJW0lGKAGJHIDY0UIrVQZGJhMqYQiWM0LWYoUvAdBhBJYzRdRijS4B0OCHZYYLTWSboWoxwyhgCTYsFAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t, Retailer = _t, Brand = _t, QTY = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Retailer", type text}, {"Brand", type text}, {"QTY", Int64.Type}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1, Int64.Type),
    #"Added Custom" = Table.AddColumn(#"Added Index", "Custom", each List.Sum(List.FirstN(Table.SelectRows(#"Added Index",(x)=> x[Retailer] = [Retailer] and x[Brand] = [Brand] and x[Index] >= [Index])[QTY],4)))
in
    #"Added Custom"

Best Regards,
Gao
Community Support Team

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If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

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[Syndicate_Admin]

Can you indicate where the result differs?

[Syndicate_Admin · Accepted solution]

Your "Next 4 dates"  is ambiguous.  Did you mean "current row plus next three rows"?  Did you mean "current date and next three days?

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjDUByIjAyNjJR2lCCB2BGJDA6VYHTS5SKicKVzKCF2bGaYUTJcRXMoYXZcxphRIlxOKXSZ4nGiCrs0Ij5wh0MxYAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t, Retailer = _t, Brand = _t, QTY = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type date}, {"Retailer", type text}, {"Brand", type text}, {"QTY", Int64.Type}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Sum Next Four", (k)=> List.Sum(Table.FirstN(Table.SelectRows(#"Changed Type", each [Retailer]=k[Retailer] and [Brand]=k[Brand] and [Date]>=k[Date]),4)[QTY]),Int64.Type)
in
    #"Added Custom"

[haoqizha]

Hi, thanks for your reply. It meant to be the next 4 "time period", for exmaple on the row of Day 1, it sums and shows the sum of QTY from D2 to D5, with its same brand and retailer.

I think you method is close to the final result I want to get, but it doesn't sum to the right QTY.