Flow variables not showing in Variable Expressions/Java Edit Variable

[harrytuttles]

This seems like a bug. A flow variable produced by the previous node does not show in the next node’s list of variables, a Variable Expressions node. It’s also missing from the Java Edit Variable node list of variables. Specifically:

Outgoing node (Table Row to Variable) creates flow variable “HoursFromLastDate”.

The new flow variable shows up after executing the node in its Variable Output table and it has a value (21).

But the flow variable does not show in the next node, Variable Expression. It is not listed under “variables”

Same happens if I replace Variable Expression with Java Edit Variable. Still not listed.

[ArjenEX]

Hi @harrytuttles

If you copy paste the images into the textbox when replying they will automatically upload. I’d guess there is something misconfigured so the screenshots or even a workflow would definitely help

[ArjenEX]

I see that you managed to get them uploaded The issue is here the field is of type long. KNIME is not very good with it. It’s not really a bug rather a missing feature which has been open for a quite a lengthy time.

Use flow variables with datatype long

I have a database query like “SELECT count(*) AS numberOfCols FROM …”. I put the result in a flow variable with the node “Table Row to Variable” because I would like to use the value of numberOfCols in the “Rule Engine Variable”. Now the variable has the datatype long and I can’t use it in the “Rule Engine Variable”. Does anyone can help me to change the datatype? Thanks a lot.

Long variable not shown in "DB Query Reader" but String variable is shown

Hi, this bug (?) almost drew me crazy. Using KNIME 4.3.2 I created a (Long) flow variable within a loop and wanted to access it in the “DB Query Reader” but it was not shown in the “flow variable list”. On the other hand it was show in the flow variables tab. After some testing I found out that the data type seems to be the problem. If I convert it to String it is shown in the “flow variable list”. Here are screenshots of the workflow: [knime-var1] and of the tabs in the “DB Query Reader” […

Suggestion: Support more Flow Variable data types in Java scripting

Hello again, the Java scripting nodes can currently only work with 3 types of Flow Variables: int, double, string. Other data types exist (long, bool, Path, array variables, …) but they’re only compatible with Java scripting as Columns. Accessing those Flow Variables via code doesn’t work: getFlowVariable("myLong", tLong) only gives the error message “The flow variable with name “myLong” does not exist”. Doing getCell("myLong", tLong) works however. This feels like an artificial restriction t…

I’d say you are better off converting it to another datatype (like int) that is supported.

PS: In cases like this, a double flow variable connection is not required

[harrytuttles]

Thank you. Can’t beat the good ol’ “It’s not a bug it’s a feature” ha ha… Anyway thank you for the quick response!

[takbb]

lol, @harrytuttles , it reminds me of some Microsoft documentation on VB3 back in the late 90s for what I would have considered to be a bug concerning default OK buttons on a form:

This behavior is by design. This design is being reviewed.