Looping through rows to find the largest link

Hi Anonymous ,

According to your description, here's my solution.

1. Create a custom column.

Length = Text.Length([Link])

2. Create another custom column.

Output = let 
T=Table.SelectRows(#"Added Custom1",(x)=>Text.Start(x[Link],1)=Text.Start([Link],1))
in 
Table.SelectRows(#"Added Custom1",(x)=>Text.Start(x[Link],1)=Text.Start([Link],1)and x[Length]=List.Max(T[Length]))[Link]{0}

Get the correct result:

Here's the whole M syntax:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUXIC4oAgfxcg5eikFKsDEXVGEnUGi4JEXJDVOruAxZ3QVDs5ww0JRRIOBYuCmJ6ohnjCTYEgqCPC4AJhWPnOSBqc4WbDRSBuC0UIQez3RFGDzepYAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Parent = _t, Child = _t, Param = _t, Link = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Parent", type text}, {"Child", type text}, {"Param", type text}, {"Link", type text}}),
    #"Added Custom1" = Table.AddColumn(#"Changed Type", "Length", each Text.Length([Link])),
    #"Added Custom" = Table.AddColumn(#"Added Custom1", "Output", each let T=Table.SelectRows(#"Added Custom1",(x)=>Text.Start(x[Link],1)=Text.Start([Link],1))
     in 
     Table.SelectRows(#"Added Custom1",(x)=>Text.Start(x[Link],1)=Text.Start([Link],1)and x[Length]=List.Max(T[Length]))[Link]{0}),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Length"})
in
    #"Removed Columns"

I attach my sample below for your reference.

Best Regards,
Community Support Team _ kalyj

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