How to use each expression in M Language

[Anonymous]

Hello Community, 

I am learning M language (let-in structure), and I have a question relevant to 'each' expression

The online course/video I am taking, is teaching how to use each.

I try to use the same function and coding to group up something for a try.

But the Query gives me an error like this:

Saying "Expression.Error: There is an unknown identifier. Did you use the [field] shourthand for a _[field] outside of an 'each' expression?"

I am using Microsoft Office 365 ProPlus, Excel Version 1905.

Anybody can help me on the each expression blockage?

[Nolock · Accepted solution]

Hi @Anonymous,

the problem is that the second parameter of Table.Group should be text instead of column identifier.

Custom1 = Table.Group(#"ChangedType", "Tasks", {"ML Test", each _})

instead of

Custom1 = Table.Group(#"ChangedType", [Tasks], {"ML Test", each _})

You can also read more about that in the PowerQuery Documentation: Table.Group

[Anonymous]

Tks sooo much @Nolock. It works now.

At first I thought it's the each key expression went wrong.

Thank you very much.