Skip to main content
Solved

Weird behavior of FeatureMerger - Some features aren't output through any port

  • September 5, 2022
  • 6 replies
  • 213 views

timotheebecker
Contributor
Forum|alt.badge.img+3

Hi,

I'm using a FeatureMerger to check that two files contain the same features based on their attributes.

Apparently, they don't seem to contain the same features although I thought they would. I must be missing something in the data. That's allright, FME's there to help me isn't it :)

But strangely, the features which are not merged are not output by the UnmergedRequestor port of FeatureMerger. Isn't that weird ?

 

All requestor features aren't output

Best answer by timotheebecker

@Mark Stoakes​ suggeted to use the avanced reader parameter "Read blank cells as :" null instead of missing. And that solves the problem. strangely, I don't see his post anymore...

This post is closed to further activity.
It may be an old question, an answered question, an implemented idea, or a notification-only post.
Please check post dates before relying on any information in a question or answer.
For follow-up or related questions, please post a new question or idea.
If there is a genuine update to be made, please contact us and request that the post is reopened.

6 replies

timotheebecker
Contributor
Forum|alt.badge.img+3
  • Author
  • Contributor
  • September 5, 2022

Hey. I solved the problem with a NullAttributeMapper transformer. But still, I don't understand why the features weren't output through the UnmergedRequestor port.


Forum|alt.badge.img+2
  • September 6, 2022

@timotheebecker​ If you can attach the sample data we can look into the why's in more detail.


timotheebecker
Contributor
Forum|alt.badge.img+3
  • Author
  • Contributor
  • September 7, 2022

Hi @markatsafe.

Here attached is a workbench and data. I have come against the same problem again with different datasets.

Thanks in advance.


Forum|alt.badge.img+2
  • September 7, 2022

@timotheebecker​ Thanks for the reproduction data & workspace. I couldn't reproduce the issue in FME 2021.2:

imagePerhaps try changing the Excel reader behaviour to treat empty cells as <null> rather then the default <missing> . <nulls> are generally treated as real citizens in FME were as <missing> implies the attribute doesn't exist.

dialogIf that doesn't work - can you identify the 5 records that do not join?


timotheebecker
Contributor
Forum|alt.badge.img+3
  • Author
  • Contributor
  • September 7, 2022

Hi @Mark Stoakes​ !

Yes, what you suggest works ! I suppose it's even better than what I had done : adding NullAttributeMappers (which do the exact same thing).

I suppose that is a good practise with Excel files to choose the option "Read blank cells as Null".

 

But I still find it weird.

Here below is a screenshot of an even simpler testcase. I attempt to merge two times the same file (just duplicated and named differently).

And it still doesn't merge when Read blank cells is set to Missing. I suppose this is "As designed". I wonder what the logic behind is...

image


timotheebecker
Contributor
Forum|alt.badge.img+3
  • Author
  • Contributor
  • Best Answer
  • September 12, 2022

@Mark Stoakes​ suggeted to use the avanced reader parameter "Read blank cells as :" null instead of missing. And that solves the problem. strangely, I don't see his post anymore...