XPath constraint to get list of objects missing an association

I’ve got an entity A linked 1:1 to an entity B. In a microflow I’d like to create instances of entity B for each entity A lacking an association so far. I assume that this should be possible as follows Retrieve list of entity A from database, with a XPath constraint that applies the filter as described above Create an empty list of entity B Go into a loop where for each object from (1) an entity B is created and added to the list (2) Commit the list (2) after finishing the loop Unfortunately, I cannot figure out the correct syntax for this XPath constraint, even though I try to follow the explanation from the tutorial. Shouldn’t it go somehow like [A.AssociationAB.B/id = NULL]? Thanks in advance for your useful hints! Philip
1 answers

Hi Philip, You use the not() function; see also: https://forum.mendix.com/link/questions/98182