Reference Row Filter - when no reference data.

Hi all, 

I have a question that I believe should have a simple solution, regarding logic to skip a reference row filter if the reference table is empty. 

My current workflow works, but I need to account for a particular scenario that could prevent it from doing so & would much appreciate any advice. 

I have a two sets of data in the same format, one bigger than the other. For example.

Material   Component   Component Cost

A                 W                      5

A                 X                       ?

B                 Y                       5

C                 Z                        10


ie, material A is produced with components W and X, costing a total of 5+'?'. 

I the use a row filter to find all missing component costs, and a groupby to find all affected materials (column 1). In the above example this will just include material A. This then goes through a separate process to find the missing value. 

Below that, I use a reference row filter to exclude all materials found in the above row filter, representing the complete data,in this case:

Material Component Component Cost

B                Y                    5

C                 Z                    10

This works for the larger data set where there is always >0 missing component costs. 

However this process is repeated for a smaller data set, which often has no missing component costs. This missing prices filter & group by have no output, meaning the reference row filter does not work. 


So what I am looking to add is If/rule logic that says if the missing prices Row filter is blank, skip to the math formula (node after reference row filter). Any recommendations as to how I can do that would be much appreciated. 


Screenshot included. 



Hi gdarling94,

The Reference Row Filter node should work even if you pass an empty table as reference. I.e., as long as the table has a column whose name is also used in the Reference Row Filter, it shouldn't matter if there is no data. In that case, no rows will be filtered, but there will not be any errors.

At least this is what I would expect from looking at your workflow :) Can you please confirm that this is the case?