Group by Chunks of pre-determined delimiters/keywords

[takbb]

Hi @jarviscampbell ,

I thought I’d take this opportunity to show-case a new component of mine. One of the less intuitive aspects of the solution for this workflow is the mechanism to join using regex patterns. The standard KNIME joiner nodes do not provide a facility for non-equi-joins (e.g. wildcards, regular expressions and ranges).

After assisting with your workflow, I decided to create a set of components which use the built-in H2 database behind the scenes to help bridge this gap.

The attached shows how the Join Regexp_Like component can simplify that part of the workflow, making it more readable and intuitive.

I have left the old mechanism at the top, and added the new variation at the bottom

GroupBy-alternative with regex join component.knwf (165.1 KB)

There are some other minor changes as a result but hopefully you may find such a component useful in future. You can see the full set in my other post on the subject:

Workflow Demo Joiner Components

Something that comes up from time to time on the forum is the ability to provide joins between tables where the join isn’t an exact match. For example, the ability to join one table to another based on a date range, wild cards or regular expressions. There are a couple of general ways of achieving the required results. One is to use a cross joiner to match all rows with all other rows, and then use a Rule Engine to see which rows actually meet the required condition, and then applying a row fi…