Question about Retrieve in Microflow

I need to retrieve the Title and Description attributes in the ServicePackage Entity. The problem is that I do not have an association available in the microflow so I have to use Xpath to filter down the results from the retrieve. The only value that I have in this microflow is the _ID in the WO_Details entity.  What would the Xpath look like to accomplish this? Note: the _ID in both entities are different values so I am unable to use that. 
2 answers

I figured it out. Thanks for your comments. 


Why do you have _ID attributes and why can't you use an association?

Everything tells me that you are not using the strength of mendix in the right way.

  1. Never ever implement your own IDs
  2. Always use the strength of associations
  3. Use the Mendix generated ID's
  4. Use associations in your constraints


Answering your question;

You can't retrieve attributes, you always will retrieve whole records/objects of an entity. Which results in a $Variable containing the object.

Retrieve of a (set of) objects constraint by a XPath like this; [Attribute = value]

Where attribute is part of your queried entity and value is either a hardcoded value', a singulair $Variable or a object variable $ObjectVariable/value