Missing data from double-loop fed SQL query

KNIME Analytics Platform
1

Dear All,

I'm trying to feed a DataBase Query with a double Table Row to Variable Loop structure:

It works perfectly in almost every cases (for one flow running it means around 600 SQL queries) but it looks that I randomly miss the result of 1-2 from this 600 SQL queries at almost every flow. I've checked the debug level log but couldn't find any error messages.

If I use the same flow just for the missing scope I'll get back the data from database without any problem.

Do you know about any bugs that could case issues like this?

Thank you in advance!

Bests,

Zsolt

 

 

2

That's a tricky problem. What you you mean by "miss the result"? It probably doesn't fail (because the loop would abort)? So is the output empty then?

You could add a Java Snippet node downstream of the node that potenitally misses the result with this statement:

if (ROWCOUNT == 0) {
    logError("Output is empty");
}


Afterwards you can search that string in the knime.log and see if there is any interesting output further up in the log file.

Sorry, tough error tracing but that's the best I can come up with.