If refering to another file


I would like to know if it is possible to create an If refering to another file and not the same file.
i have too much data to write it one by one (500,000)

for example:

i especialy need the operators (c,=,!=,>,<,…)

i did it in the past by modifying the .transform but maybe there is an easier way to do it

Thanks in advance

Perhaps you can use the Lookup transform. But I need a few more details.

Can you give me a simple example with 2 input datasets (just a few rows each) and the output you want.