PowerQuery add a custom colum with the min date from another table

[MikeSolvesBI]

Hello,

How can I add a custom column to a table with the value which is the minimum date from a field in another table?

Thank You,

Michael

[Anonymous · Accepted solution]

Hi @MikeSolvesBI ,

According to your description, here are my steps you can follow as a solution.

(1) This is my test data.  

(2) Paste the following code into Advanced Editor.

Table2：

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtI1ACGlWB0cXFNdAzMkrrmugYVSbCwA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Date = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type date}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each Table.Group(#"Changed Type", {}, {{"Min_date", each List.Min([Date]), type nullable date}})),
    #"Expanded Custom" = Table.ExpandTableColumn(#"Added Custom", "Custom", {"Min_date"}, {"Min_date"})
in
    #"Expanded Custom"

Table：

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlSK1YlWMgKTxmDSBEyagkkzpdhYAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [id = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"id", Int64.Type}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each #"Table2"[Min_date]{0})
in
    #"Added Custom"

(3) Then the result is as follows.

Best Regards,

Neeko Tang

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