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Anonymous's avatar
Anonymous
Not applicable
6 years ago
Solved

Cannot convert value null to type List

I have a data set in table as below :            The RCA field has the values coming from an API in the form of records as below which i want to show as a single record separated by "-" ...
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  • v-lili6-msft's avatar
    v-lili6-msft
    6 years ago

    hi Anonymous 

    You could try this simple way as below:

    Just add a steps that replace error with null (or other value).

     

    or just nested it in your formula as below:

     

    =Table.ReplaceErrorValues( Table.TransformColumns(
    #"Renamed Columns2",
    {
      {
        "RCA", 
        each Combiner.CombineTextByDelimiter(" - ")(
	  List.Transform( _ , each if _ = null or _ = "" then 0 else [value] ) 
        ),
	type text
      }
    }
  ) , {{"RCA", null}})

     

     

    Regards,

    Lin

Anonymous's avatar
Anonymous
Not applicable
6 years ago

Hi Anonymous ,

 

I think the problem is that the "null" value is not list type, even you change it to "-", it's also a string type, not list type.

So you can't use the list.transform() function to it.

 

I think you need to do the if-else firstly, for example, just using:

if RCA is null then 0

else "your combine / list.transform() function

to do it.

 

Please try.

Aiolos Zhao

  • Anonymous's avatar
    Anonymous
    Not applicable
    6 years ago

    Tried it but still same issue , output http://prntscr.com/qkoyuv

    = if "RCA" is null then 0 else (Table.TransformColumns(
    #"Renamed Columns2",
    {
      {
        "RCA", 
        each Combiner.CombineTextByDelimiter(" - ")(
	  List.Transform( _ , each [value] ) 
        ),
	type text
      }
    }
  ))