OK, I’m sure the answer is simple, but sadly I just don’t “get it”. I’m a programmer from the early '80s, but I’m having trouble getting the “concept” behind how KNIME processes rows in a table.
For example, in SQL, a single SELECT statement processes a whole group of rows at the same time. Something like SQL Server T-SQL, or Microsoft VBA (Microsoft Access) lets you process a row at a time.
How do I process one row at a time in KNIME?
Conceptually, I want to “loop” through all the rows in a table (perhaps 1,000 rows), and examining each row individually, update the rows, and save them in a new table.
For example, say I have a table “Table A”, with rows:
NAME VALUE RESULT
Note: I had trouble formatting the table above. The letters should be in the “NAME” column, the numbers, in the VALUE column, with RESULT column blank (what I want to update in a KNIME workflow).
I want to process the rows of “Table A”, create a new table (“Table B”), with the RESULT column being a function of the VALUE column (perhaps VALUE*2). This is an artificial example, but hopefully you get the idea.
This grizzled old C, Java, SQL, FORTAN, assembler, VBA programmer is confused…
…I can’t tell if I just:
- Connect nodes sequentially (no loop)?
- Use a loop?
- Use a recursive loop?
I have both the Beginner’s Luck and Advanced Luck books, but I’m just missing the “concept” of how KNIME does this. Oddly enough I’ve been able to do other workflows OK, but the above is really confusing me!