Replace every "?" with a "0" as an DOUBLE

[Jana_Tuerlich]

Hello all,

I have the following problem: Using a loop, I read in several tables, which are then listed below each other in rows. This works so far quite well.
Problems arise as soon as I have a “?” value. Then the data format within a column is no longer the same and KNIME gives me an error.
Do you have an idea what I can do?
My idea was to simply replace each “?” with a “0”. However, this fails because of the handling by me.
I can replace all “?” via the “Missing Values” node, but then they often become a string instead of a double.
So what can I Do?

Many thanks in advance!

[elsamuel]

Problems arise as soon as I have a “?” value. Then the data format within a column is no longer the same and KNIME gives me an error.

If I understand the problem correctly, it can be solved by enabling “Allow variable column types” in the configuration of the Loop End node.

[julian.bunzel]

Hi @Jana_Tuerlich,

you can convert column types by using the String To Number and Number To String node.
The new Table Manipulator node lets you change column types as well (plus a bunch of other things as column filtering, renaming and resorting).

Best,
Julian