I would appreciate help to solve the following problem:
In Excel sheet I have a column set as ‘number’. When Knime reads this column through ‘XLS Reader’ note, it is being recognized as 'DataCell'.
Actually, the ‘number’ column content in Excel is empty (there is just the header cell in the frist row), and maybe because of that Knime is misunderstanding the data.
a) By using ‘column rename’ node I tried to change the DataCell column to IntCell, but in the combo box the only available option is ‘stringvalue’. Why ‘intvalue’ isn’t available? How could I change DataCell column to IntCell inside Knime?
b) I am also using another table from Excel (same structure than the mentioned before), in which there is number content in the column and Knime recognizes it as IntCell properly.
Anyway, a bigger problem appears when I concatenate in Knime both tables (the one with column as ‘DataCell’ and the other ‘IntCell’). The output column is now ‘Non-Native [interface org.knime.core.data.DataValue]’. Then my workflow stuck! How to solve this problem? Actually, it seems that by solving (a) this latter problem wouldn’t even appear!
These problems of column types come up time and time again with the column rename node not doing the desired job of changing the typecast of a node.
really, really need a column typecast node so that you can easily change a column type. Please knime team implement this.
so I am afraid there is no easy answer to a. This problem comes up regularly around these non native types that get generated which cause havoc in workflows, and converting structure columns to string data cells is also very challenging.
One option for a. is to try the string to number node, and select Intcell from the option in the node.
Another option is to convert your table to a csv file first and then read this into knime where you can choose the column type within the file reader.
Im pretty sure the string manipulation node changes the typecase of a column doesnt it?
so if you use something like toInt($column_name$) in the string manipulation node I think that would solve the problem. The toInt should change whatever is in the cell to an Integer. They also have a double and long function in the string manipulation node as well