Data flow - grouping - all rows loses data types on expand

[ruthhacche]

I can do this in a dataset -  grouping by a field and all rows so that I can then expand back out all the rows after the grouping. No issues with data types. 

when I repeat exactly the same thing in a dataflow I have to reassign the field data types of all columns expanded out.   Am I doing something wrong?

[v-stephen-msft]

Hi @ruthhacche ,

You can try data type detection.

Reference: https://docs.microsoft.com/en-us/power-query/data-types#data-type-detection

Best Regards,

Stephen Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[lbendlin]

Not clear what the issue is. Can you post a sanitized version of the Power Query code?

[ruthhacche]

This is what I am doing in my dataflow - it loses all the datatypes when it returns due to the bold text:

#"Grouped rows" = Table.Group(#"batch name", {"Item Code Original"}, {{"all", each _, type nullable table}, {"Original Batch Name", each List.Min([Batch Name]), type nullable text}}),

  #"Expanded all" = Table.ExpandTableColumn(#"Grouped rows", "all", {"ID SFC Item", "Item Short Type", ........etc etc long list of fields............, "Batch Name"}),

In my dataset, when I group and then expand all it adds the different bold code  {"all", each _, type table [ID SFC Item=text, .... long list of all my columns eachwith their format]}.   This keeps all the formats in the expanded table.

In both cases I am just using the group ribbon tools in the same way.  I wonder what I am doing differently because I do not particularly want to type in all the columns and their formats into the dataflow.  It is probably just a  box I am not ticking or something.