Is there a way to rename a variable in Knime?

[prashant7526]

Hi All,

I was looking for the same solution posted on below link:

Is there a way to rename a variable in Knime? - KNIME Analytics Platform - KNIME Community Forum

The above post is closed, so I cannot answer it.

The Anser is: Yes, there is a way to rename a Variable you can use Variable Expression Node

[sanket_2012]

Hi @prashant7526 ,
Welcome to the KNIME forum!

Yes, absolutely; that would be another way to rename a variable.

Thanks for posting this, and happy KNIMEing

Thanks,
Sanket

[tqAkshay95]

Hello @sanket_2012 ,

Yes, it is possible to update the variable name in KNIME by using the Variable Expression node.

Variable Expressions

[pstedem]

Hi @prashant7526,

thx for your hint, but I still don’t get it right.

What exactly do I have to do to rename/update a variable’s name? I encountered, that the checkbox for “Replace Variable” just replaces the old value, but doesn’t change the name of the variable.

If I want the right named variable I only get it without replacing it and save it as a new variable, that sits right next to the old one, with no chance of deleting the old one.

Do I oversee something? Please help.

Thanks

[takbb]

I agree @pstedem , I don’t see how Variable Expressions can “rename” a variable. It can copy it, but the old variable surely remains.

@prashant7526, and @tqAkshay95 are you sure it can rename a variable? I’d certainly be interested to see this demonstrated…

[ArjenEX]

You can probably wait until forever

As per the OP’s link, this topic has been around for ages. It’s probably for a reason why KNIME devs aren’t very keen on implementing this. My assumption would be that variables either originates from table columns (which you can rename in advance) or by manual creation (whereby you have control of the name.) So I’m curious about the use case where having such a node would come into play.

[takbb]

@ArjenEX

You can probably wait until forever

Lol @ArjenEX

@prashant7526 , if you do have a use case where perhaps a specific node creates a variable with a name over which you have no control, and you actually want it to have a different name…

The only way I know of achieving that is to create a component and have the original variable creation occur inside the component.

You would then replicate that variable using something like Variable Expressions and then on the exit from the component you only let the new variable leave the component (by configuring the Component Output node).

All flow variables created inside a component do not exit the component unless explicitly allowed to leave.

To be honest you have to really want the name to be different. It feels like a lot of effort for a variable name. (welcome to the KNIME forum, btw)

[pstedem]

Thank you

For me the use case is in that cases, where variables originate from table columns/rows (i. e. ‘Table Column to Variable’).

@ArjenEX You are right with, that I could work on the naming in advance. But in some cases I would find it more convenient to update the variable’s name afterwards. (i. e. in ’ Variable Expression Node’)

The method of creating the variable in a component sounds interesting. But like you say @takbb: It seems like a lot of effort. I wouldn’t choose that method either.

So, in conclusion I will have to find a way to control the variable’s names beforehand, rather than get confused with meaningless variable’s names.

[prashant7526]

I mean, we can create a new variable with a different name. In my case, I needed a specific name. So, I copied the older stay, but the point is that it solved my purpose of having a specific name for the Variable (that is why I wanted the option of renaming, right?)

[takbb]

Hi @prashant7526, I’d suggest you are actually copying or duplicating a variable rather than renaming it, but if your aim is simply to have a new variable (with a specific name) that contains the original value then that’s great.

There is currently no facility to actually rename a variable in KNIME, such that the old variable name ceases to exist, but you’re right that this may not matter.