List operation substract

It is friday!!! So maybe I am already on my weekend break... I thought I had a very simple issue, but it turned into a headache today. I want to use a 'list operation'in a Microflow to determine the difference between 2 imports of data. In order to tell the imports apart they have a header-record (only holds date-time) and a lot of fields in the entity below the header. The problem is: when I use substract, I always get all the records in the NEW import back as being 'New'. Which is not true. So I wonder if the reference to  header record is evaluated in the 'substract' as well and not only the fields in lists that I compare. Anybody any ideas... I cannot really determine from the documentation.   Thanks and have a great weekend!! Mark  
1 answers

Hi Mark,

The "Subtract" list operation is looking for object equivalencies (via the Mendix Identifier, I believe) and not duplicate data.  To my knowledge, if you have two entities with the same attributes, they will have different identifiers and will not be removed via the subtract list operation.  

A possible solution would be to use the "Find" list operation that, if the object was found, then you would know that the object is a duplicate and can remove it from the list (this would be iterative, however).