Handling Nulls in DMNs

BPMN & Modeling Discussion & Questions
1

I’ve seen a few posts asking how evaluate for Nulls in a DMN table but haven’t seen a post with a straighforward solution. With lots of googling and testing I’ve discovered the following that works for me.

  • For strings use “”
  • For integers use null
  • For doubles use null

I hope this helps.

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1 Like
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@Alain_Jaques thank you for sharing :+1:

It is also a good practice to use an empty condition (i.e. input entry) for these cases.

Note that it behaves in Camunda Platform 8 a bit differently. You would compare null always with null, also for strings. See the following example:

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Best regards,
Philipp

3

Thanks Philipp.

That is a good improvement on version 8. It is consistent and intuitive in specifying null for both data types. I wonder does it work for Date and Boolean too?

Point taken on on the empty condition, by which I understand you leave the input condition blank such that it displays the minus sign -.

However in our case we were looking specifically for nulls which then have a specific output that is different for other values that could pass the empty test.

Kind regards
Alain

4

Yes. null is available for any data type.

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