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edwardrmiles's avatar
edwardrmiles
Helper III
9 years ago
Solved

Invoking function causes "Expression.Error: We cannot convert a value of type Record to type Number"

    Hi, I'm trying to create a function that will rename all columns in a table., but when I invoke the function (from both the query editor and navigation panel) I get the folliwng error:   An e...
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  • MarcelBeug's avatar
    MarcelBeug
    9 years ago

    So why do you want to rename your columns, is it:

    1. Because you get the error of duplicate column names, or

    2. You want to rename your columns for another reason, but as a result you get duplicate column names?

     

    In any case if you want to rename your columns so there won't be any duplicates, then you need to find some other solution for any duplicates, typically that would be adding a seqeunce number, e.g. if you have multiple "INFO CARD LINK" columns, then the first can be "INFO CARD LINK", the second "INFO CARD LINK.1", the third "INFO CARD LINK.2"  and so on.

     

    That would require a complete different approach.

     

    Note: in Power Query, column names are case-sensitive, but when loading the result, you'll get an error (I guess that is the error you mentioned in your previous post).

MarcelBeug's avatar
MarcelBeug
Community Champion
9 years ago

Technically spoken you provide a record [Comparer = Comparer.OrdinalIgnoreCase] as the third argument for Table.RenameColumns, where you can only provide a number: the value for MissingField.

 

Edit: you code works fine if you remove that third argument.

 

My idea would be:

 

let
    fnRenameColumns = (tableName as table) =>
let
    Source = tableName,
    ColumnNames = Table.ColumnNames(Source),
    Transform = List.Transform(ColumnNames, each {_, Text.Upper(Text.Replace(_,"_"," "))}),
    RenameColumns = Table.RenameColumns(tableName,Transform)
in
    RenameColumns
in 
    fnRenameColumns

 

 

edwardrmiles's avatar
edwardrmiles
Helper III
9 years ago

Thanks, so I added that 3rd argument because when I don't use it I get this error:

 

An error occurred in the ‘fnRenameColumns’ query. Expression.Error: The field 'INFO CARD LINK' already exists in the record.
Details:
    Name=INFO CARD LINK
    Value=

 

  • MarcelBeug's avatar
    MarcelBeug
    Community Champion
    9 years ago

    So why do you want to rename your columns, is it:

    1. Because you get the error of duplicate column names, or

    2. You want to rename your columns for another reason, but as a result you get duplicate column names?

     

    In any case if you want to rename your columns so there won't be any duplicates, then you need to find some other solution for any duplicates, typically that would be adding a seqeunce number, e.g. if you have multiple "INFO CARD LINK" columns, then the first can be "INFO CARD LINK", the second "INFO CARD LINK.1", the third "INFO CARD LINK.2"  and so on.

     

    That would require a complete different approach.

     

    Note: in Power Query, column names are case-sensitive, but when loading the result, you'll get an error (I guess that is the error you mentioned in your previous post).

    • edwardrmiles's avatar
      edwardrmiles
      Helper III
      9 years ago

      ah, I get it now... silly error on my part.  My objective was to just to imporve the readability of column names, but that renaming has created a duplicate that I didn't originaly see.  I should have actually though about what the error message was telling me...

       

      Your solution works perfectly and I greatly apprecaite your expert help!