Java Snippet - values based previous row

KNIME Analytics Platform
1

Hello all,

is possible to make operation in Java Snipper, which returns value based on value in previous row and in the same or another column? 

UseCase:

I have table with Customer_ID, Order_id and Order_date columns and I want to fill Order_of_orders according to order of orders scpecific for each customer.  

Example of table:

Customer_ID Order_id Order_date Order_of_orders
1 1004 01/06/2016 1
2 1001 01/01/2016 1
2 1006 01/10/2016 2
2 1007 01/11/2016 3
3 1003 01/06/2016 1
4 1002 01/04/2016 1
4 1005 01/10/2016 2

I know how to logically solve this  as I already did in other ETL tool with has Java sripting node, but I can´t find proper syntax for KNIME Java Snippet node.

Thanks you very much for any help:)

1 Like
2

Hi Jiří 

You can either define a global variable in the snippet and keep track of the previous value using it, or use a lag column node to move the previous value into a new column in the same row

Attached is a workflow example for both

David

 

 

 

3

Hi David,

thx for advice, should solve my problem :)

Jiří