Expression.Evaluate code does not work because of unknown identifier

[JVos]

Why does below code not work, and raise an error ("Expression.Error: There is an unknown identifier. Did you use the [field] shorthand for a _[field] outside of an 'each' expression?") caused by the Expression.Evaluate part?

let
    TableA = Excel.CurrentWorkbook(){[Name="tblRoute"]}[Content],
    TableB = Excel.CurrentWorkbook(){[Name="tblBAAM"]}[Content],

    TableA_TableB = Table.AddColumn(TableA, "Outcome", each Table.SelectRows(TableB, Expression.Evaluate("(Magic) => [RouteName]=Magic[RouteName]", [Magic=TableB]))),
    Result = Table.ExpandTableColumn(TableA_TableB, "Outcome", {"Outcome"})

in

    Result

[JVos]

@AlB Thank you very much! This worked - with a minor change, because the column name is not Name, but RouteName.

JVos

[AlB · Accepted solution]

Hi @JVos 

Try

TableA_TableB = Table.AddColumn(TableA, "Outcome", each Table.SelectRows(TableB, Expression.Evaluate("(Magic) => [Name]=Magic[Name]", [ _ = _ ] )))

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