Lookup Stage Error due to Key field "A" not found

[ptc3bluedevil]

I'm receiving a Fatal Error in a lookup stage with the following message: "Error when checking operator: Key field "A" not found in input schema"

The error occurs during Startup time, not Production Run time. I have checked the obvious scenarios (View Data is working fine on all inputs and reference data, field A is mapped properly through all earlier stages of the job).

What are some other reasons this can occur?

Additionally, when I previously coded the job such that the lookup stage in question contained a Conditional expression that included field A (i.e. isNotNull(A)), I received a Compile error stating that the lookup contained a duplicate column A.

[chulett]

Search the forums for "not found in input schema" and see if any of those matches help, this has been discussed here before.

[ptc3bluedevil]

You're right -- there have been multiple discussions around this topic, but unfortunately the only successful resolution seems to be deleting all nearby stages and links, and then recoding the lookup. I have done this, and it seems to be working... but I hope this is not considered a "solution."

[oracledba]

I know this thread is old but this could help.

One reason this could occur, which is what happened with one of my jobs, is within the same lookup if you have two key columns looking up and both have the same column name being looked up to two different lookup fields.

In this scenario the not found in input schema error popped up for me.

So in the upstream transformer stage created a new field name with the lookup field name_1 and used that as one of the fields being looked up on

This solved the problem for my situation. Perhaps, something to keep in mind for the future