Combining dates as text in a grouping step

[k1s1]

Hello,

I'm trying to group so that I have columns containing text separated by commas, one of which will group dates producing this kind of output in each cell

"12 Mar 2021, 13 Apr 2021"

This is the M for the step that I have tried:

= Table.Group(#"Added Custom1", {"Referral Reference", "vs Target"}, {
        {"MDTs", each Text.Combine([Type],", "), type nullable text}, 
        {"MDT Dates", each Text.Combine(Date.ToText([Event Date],"dd MMM yyyy"),", "),type nullable text}
        })

This columns works fine, creating a list of text, separated by commas:

        {"MDTs", each Text.Combine([Type],", "), type nullable text}, 

So I tried to adapt it for the dates as below but this for this column I get and "Expression.Error: We cannot convert a value of type List to type Date."

{"MDT Dates", each Text.Combine(Date.ToText([Event Date],"dd MMM yyyy"),", "),type nullable text}

I was assuming I could simoply wrap the date field with Date.ToText, but that didn't seem to work.  What is the correct syntax /  approach?

[k1s1]

Thank you

[Anonymous · Accepted solution]

• the Text.Combine function takes a LIST as input and concatenates the various elements in a single text string.
• the date.totext function takes a DATE TYPE value as input.

in the following expression, you are asking the Date.ToText function to work on a list represented by the column content [Event Date]

{"MDT Dates", each Text.Combine(Date.ToText([Event Date],"dd MMM yyyy"),", "),type nullable text}

prova (non ho testato il codice: potrebbero esserci errori di sintassi) a cambiarla nel seguente modo, per consentire alla funzione di agire individualmente su ogni singolo elemento della lista:

{"MDT Dates", each Text.Combine(List.Transform([Event Date], (dtt)=>Date.ToText(dtt,"dd MMM yyyy")),", "),type nullable text}