Rename content of a column if a certain content in another column exists

[Petjak]

A little tricky Subject Headline... Since im quite new to the Power BI game. I'd like to know if there is a way to rename contents of for example column "b" if a certain content in column "a" exists. Somehow i dont find a fitting solution with the Query Editor. 

[Vijay_A_Verma · Accepted solution]

Yes, Table.Replace value is used for this. An example below

=Table.ReplaceValue(#"Changed Type",each [b],each if [a] ="abc" then "x" else [b],Replacer.ReplaceValue,{"b"})

See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WKk8tUtJRKihQitWJVkpMSgZyCgvBnPKSysoSILeoCEmuuFgpNhYA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [a = _t, b = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"a", type text}, {"b", type text}}),
    Custom1 = Table.ReplaceValue(#"Changed Type",each [b],each if [a] ="abc" then "x" else [b],Replacer.ReplaceValue,{"b"})
in
    Custom1

[ronrsnfld]

You can do it but you have to get into the Advanced Editor.

This code provides an example of one way to do this:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WSkxKVtJRMlSK1YlWSklNA7KNwOz0jEwg2xjMzsrOAbJNlGJjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [a = _t, b = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"a", type text}, {"b", Int64.Type}}),

    #"Look for in col A" = "ghi",
    #"Conditional Rename" = if List.Contains(#"Changed Type"[a],#"Look for in col A") 
        then Table.RenameColumns(#"Changed Type",{"b","New Col Name"}) 
        else #"Changed Type"

in
    #"Conditional Rename"