Assuming all the data is always coming in properly ordered and that EML.... string is a unique identifier for each invoice you can use a Counter with that attribute as the Count Domain (if I recall correctly that parameter was called Counter Name in older versions). It'll reset every time a new value for that attribute comes by.

New day and lots of reading up on transformers .....

It's easy with a bit of SQL knowledge (and remembering that InlineQuerier is a local sqllite database).

SQL gives the easy capability to include a row number

 ROW_NUMBER () OVER ( 

    PARTITION BY "ITEMDATA-PO_NUMBER"

    ORDER BY "INVOICE_DOC_ITEM"

  )-1 as newDOC_ITEM

Ahhh thanks @Hans van der Maarel​ ...

I'm running 2020.1 version of FME and that option doesn't exist.

Time to work on the upgrade process. having to uninstall FME Server just to install is a bit of a pain.

Thanks again

In 2020 the Counter does have that option, but it's called differently, "Counter Name" if i recall correctly, so no need to update FME Server just for that 😉

Head banging icon....

Less haste more speed...

Thanks so much.

FME is a product in 2 halves.

On the one hand really good and does a huge amount...

On the other really frustrating as so many transformers do such a similar thing and the terminology doesn't always jump out to me...

Why use a simple Counter when I can write a nice bit of SQL and use the Inline Querier

:-)

Thanks again.

Yeah, I totally understand it can be daunting sometimes. With 500-ish transformers it's not always easy to figure out which one you need to perform a certain task. Unfortunately, other than trying to break down your process into small chunks and building up experience I still haven't found the magic way to quickly get to the point where you immediately know which transformer you need. To be perfectly honest, I think I'm not saying anything too boastful if I say I'm a longtime (23 years, most of those as a Safe partner) poweruser and I probably have never used half of the transformers that are in FME right now. Nor do I know what they do.

Long story short: that's why the community is here, feel free to ask, we're happy to help. And don't be afraid to experiment 😉

Ohhh I've never been afraid to play 😎

Out of interest how would you say Power Automate / Azure Logic apps compare?

I've used FME for maybe 3 years but much longer using code; FME is good for non coders and it also self documents (to a point).

I don't have any experience with Power Automate or Azure Logic, so I really can't comment on that.

I do agree that FME is a great solution if you don't like coding. I've taught myself a number of programming languages to a somewhat competent degree over time but being visually oriented I can work a lot better and faster with FME.

👍