DISTINCT on a table to fill a Gallery? Nope!

[MisterMagoo]

I have an Excel table, "AppDetail", as a source for my app.
It contains several columns, one of these being "Country". I want to fill a GALLERY with the DISTINCT countries I find in this table. Ok, go! Step one: I assign the ITEMS property of the gallery the following formula:

Distinct(AppDetail, Country)

Step two: I assigne the TEXT property of the label in the gallery the value Country (i.e. the field name I DISTINCTed).

Super easy, isn't it? WRONG! See the result:

There is no error on the formula, but the "Country" value is not retrieved by the gallery: "invalid name"!

(EDIT: if a use the same Distinct above to fill a DROPDOWN "items" property, it works fine!)

Look what happens if I simply replace, in the ITEMS property of the gallery, the DISTINCT formula above with the plain "AppDetail" table, without changing anything: it works GREAT!

I tried already what suggested in this post. Basically, I created a collection "AllCountries" like this, using the AppDetail table as source. 

ClearCollect(AllCountries, Distinct(AddColumns(AppDetail,"IDCountry",AppDetail.Country).IDCountry,IDCountry))

I put "AllCountries" on the ONVISIBLE property of the screen, I used this Collection in the ITEMS property of the gallery: same result, cannot find the IDCountry value! 

Oh gosh, where is my mistake?!? I love PowerApps but I also hate it! 🙂

Thanks folks!
Bye,

A.-

[MisterMagoo]

So, while being sad for not having got any help so far :-), keeping on with my try&fail approach, I've been able to solve it!

Unbelievable. The original DISTINCT in the ITEMS of the Gallery is fine:

Distinct(AppDetail,Country)

The only thing is that I cannot refer to the "Country", inside the gallery elements, using "Country" as I was doing. I must use:

label.text = ThisItem.Result

It works! I still don't understand why, though. I just used what is proposed by the "ThisItem" element.

[RusselThomas · Accepted solution]

Hey MisterMagoo,

Distinct always returns a single column table where the column name is "Result" by default

If you collect the results from a Distinct() action you can see this behaviour;

Collect(collectDistinctResults, Distinct(source, columnname))

Then go view the collection in the collection menu.

To retain the columnname for your sanity, you can use 

RenameColumns(Distinct(AppDetail,Country), "Result", "Country")

Then your gallery reference can be a bit more relevant with ThisItem.Country 

Like I said, only for your sanity and the sake of 'keeping things tidy' - but if you understand that a Distinct always returns with the column "Result" and you're happy with it, you can just reference ThisItem.Result and avoid the overhead 🙂

Hope this helps,

RT 

[MisterMagoo]

Thanks Russel!!