Compare columns in 2 the same structured tables.

Hi jaryszek 

I think I made it! You could try below codes to create a function. Download the attachment for details.

(mapTable as table, defTable as table) =>
let
    // mapTable = TAbleMap,
    // defTable = TableDef,
    //Please keep the mapTable before the defTable in below Source step
    Source = Table.Combine({mapTable, defTable}),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(Source, {"TableName", "Key"}, "Attribute", "Value"),
    #"Changed Type" = Table.TransformColumnTypes(#"Unpivoted Other Columns",{{"TableName", type text}, {"Key", type text}, {"Attribute", type text}, {"Value", type text}}),
    #"Replaced Value" = Table.ReplaceValue(#"Changed Type","Name_To_Skip",null,Replacer.ReplaceValue,{"Value"}),
    #"Grouped Rows" = Table.Group(#"Replaced Value", {"Key", "Attribute"}, {{"Values", each _, type table [TableName=nullable text, Key=nullable text, Attribute=nullable text, Value=nullable text]}}),
    #"Expanded Values" = Table.ExpandTableColumn(#"Grouped Rows", "Values", {"TableName", "Value"}, {"TableName", "Value"}),
    #"Filled Up" = Table.FillUp(#"Expanded Values",{"Value"}),
    #"Removed Duplicates" = Table.Distinct(#"Filled Up", {"Key", "Attribute", "Value"}),
    hasDifferences = List.Contains(Table.Column(#"Removed Duplicates", "TableName"), "TableDef"),
    #"Filtered Rows" = Table.SelectRows(#"Removed Duplicates", each ([TableName] = "TableMap")),
    #"Removed Columns" = Table.RemoveColumns(#"Filtered Rows",{"TableName"}),
    #"Filtered Rows1" = Table.SelectRows(#"Removed Columns", each ([Key] = "cat")),
    #"Pivoted Column" = Table.Pivot(#"Filtered Rows1", List.Distinct(#"Filtered Rows1"[Attribute]), "Attribute", "Value"),
    table1 = #"Pivoted Column",
    table2 = #table(
    {
      "Key",   // First Column Field Name
      "Col"   // Second Column Field Name
    },
    {}
  )
in 
    if hasDifferences then table1 else table2

Regards,
Community Support Team _ Jing
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