How do I get previous value from last month into a new column?

[KH11NDR]

Hi Guys

How do I get previous value from last month into a new column?

Date	Cumulative  Sales	Previous Month **bleep** Sales
01/06/2018	10	0
01/07/2018	20	10
01/08/2018	30	20

[Anonymous · Accepted solution]

@KH11NDR here you go. Use the PARALLELPERIOD function to get the desired result. 

[Anonymous]

Hi @KH11NDR, In order to achive Lag(previous value) you need to follow below steps. 

Create two index column one starts with 0 name it as Index0 and other starts with 1 name it as Index1

Do left Join on same table on condition will be Maintable.Index0 = SelfJoinTable.Index1.

Expand the column and select the "previous value" column which will be ur Lag column.

Sample query:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCkrMKlXSUTI0MlaK1QFxc0FcEzMzMNc7sygxD8g3UoqNBQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [Name = _t, Rank = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Name", type text}, {"Rank", Int64.Type}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1),
    #"Added Index1" = Table.AddIndexColumn(#"Added Index", "Index.1", 1, 1),
    #"Merged Queries" = Table.NestedJoin(#"Added Index1",{"Index"},#"Added Index1",{"Index.1"},"Added Index1",JoinKind.LeftOuter),
    #"Expanded Added Index1" = Table.ExpandTableColumn(#"Merged Queries", "Added Index1", {"Rank"}, {"Lag.Rank"}),
    #"Sorted Rows" = Table.Sort(#"Expanded Added Index1",{{"Index", Order.Ascending}}),
    #"Removed Columns" = Table.RemoveColumns(#"Sorted Rows",{"Index", "Index.1"})
in
    #"Removed Columns"

Output screesnshot:

 

And finally replace null with zero.

 Hope above solution will help in your case.

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Suman152

[KH11NDR]

There ha to be an easier way for sure? Thanks Suman, but Power BI, Must have an easier way,.

[Anonymous · Accepted solution]

@KH11NDR here you go. Use the PARALLELPERIOD function to get the desired result. 

[KH11NDR]

@Anonymous

I'm still not getting any figures, I've added my date to a master calendar too.

[Anonymous]

@KH11NDR Check the format of the date field? The data set I used is pretty simple and straight forward. Here is a snap of my model. Could you send screenshots of your model, your calculations and final results.

 

[KH11NDR]

Previous month = CALCULATE(SUM(Merge1[Cumulative Revenue]),PARALLELPERIOD(Merge1[Date],-1,MONTH))

[Anonymous · Accepted solution]

@KH11NDR Can you post screenshot of the final table where you are testing the solution, the list of values which go in it. Also are you using a calculated column or measure. I am using a measure.

[KH11NDR]

Changed it from Column to Measure and workd like a treat.

Thanks