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How to merge two get nearest previous date by using M Code ?
Hi. I am trying to get nearest previous date from other table(Table1) in Power Query not by DAX? Table1: Expected Result : Table2 (added Column1 form Table2): Any help on ...
See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test
This code is for Table2.
let Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1MNQ1NFWK1YFxgQiViyJrDBRB5RoqxcYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]), #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type date}}), BuffList = List.Buffer(Table1[Column1]), #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each [l=List.Transform(BuffList,(x)=>Duration.Days(x-[Column1])),p=BuffList{List.PositionOf(l,List.Last(List.Select(l,(y)=>y<=0)))}][p]) in #"Added Custom"Code for Table1
let Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1MAQipVgdGNdI19AAiWsMFFGKjQUA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]), #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type date}}) in #"Changed Type"You have done in the right manner. As supplying both input and output makes us give right answer.
You will need to use a try otherwise block
try [l=List.Transform(BuffList,(x)=>Duration.Days(x-[Column1])),p=BuffList{List.PositionOf(l,List.Last(List.Select(l,(y)=>y<=0)))}][p] otherwise List.Max(BuffList)Hence, following code for Table2
let Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1MNQ1NFWK1YFxgQiViyJrDBRB5RrCuEBzjMDcWAA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]), #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type date}}), BuffList = List.Buffer(Table1[Column1]), #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each try [l=List.Transform(BuffList,(x)=>Duration.Days(x-[Column1])),p=BuffList{List.PositionOf(l,List.Last(List.Select(l,(y)=>y<=0)))}][p] otherwise List.Max(BuffList)) in #"Added Custom"
See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test
This code is for Table2.
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1MNQ1NFWK1YFxgQiViyJrDBRB5RoqxcYCAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type date}}),
BuffList = List.Buffer(Table1[Column1]),
#"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each [l=List.Transform(BuffList,(x)=>Duration.Days(x-[Column1])),p=BuffList{List.PositionOf(l,List.Last(List.Select(l,(y)=>y<=0)))}][p])
in
#"Added Custom"Code for Table1
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1MAQipVgdGNdI19AAiWsMFFGKjQUA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type date}})
in
#"Changed Type"
If you make sure BuffList is sorted, then you can simply take the last element that's less than or equal to the date in the current row.
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1MNQ1NFWK1YFxgQiViyJrDBRB5RoqxcYCAA==", BinaryEncoding.Base64), Compression.Deflate)), type table [Column1 = text]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type date}}),
BuffList = List.Buffer(List.Sort(Table1[Column1])),
#"Added Custom" = Table.AddColumn(#"Changed Type", "Custom",
(row) => List.Last(List.Select(BuffList, each _ <= row[Column1])), type date)
in
#"Added Custom"
AlexisOlson
Thank you！I’ll try that too!