How To: Count, Iterate and Join Tables?


I am doing an association analysis with the "Association Rule Learner (Borgelt)"-Node. This works fine and I've got my rules.

I have some problems with the next steps:

All my rules are based on article numbers. In the next steps I want to join them with another table that contains names of articles and their article number. The joining works fine with 2-itemsets.

Problem: Some antecedents contain more than 1 item, so they are collections and I need to split them up. I use the split collection column to split them into new columns.

Now I want to count the new columns (e.g. some antecendents have 2, some 3 items) and iterate. For every column, there should be a join with the "Number-Name-Article-Table".

How can I do this in Detail? I've got some Loops etc. here but I am too new to solve this problem.


Maybe anyone can help me. Feel free for further questions.

Thanks :)

Hi New2Knime,

Have you already tried Ungroup node to split the collection column? This would put each value from the collection column into a new row. Then you could use GroupBy node: Group by your ID columns and Aggregate the count on any other column. This counts you could use in the following loops you are building.


You can find more information and example workflows on Aggregation nodes and Loop nodes in our Node Guide


Hope it helps.