custom named entity extraction

I'm trying to implement NER(Named Entity Extraction) using stanford NLP. final goal is to convert free text to query format. I created a custom dictionary and am able to extract entities and build query

people who are from newyork

I'll build query

     select * from people where region = 'newyork'

but the issue comes when the statement is negated

people who are not from newyork

How to extract negative scenario from this statement, Is there any way possible even outside of stanford NLP

Any help is appreciated

I know 2 possibilities to implement negation relation:

• Define custom property "not a ..." and apply it everywhere.
• Use knowledge database, extract LOCATIONs from data, define "not from smth" as "LOCATION is not smth".

I used second approach successfully, but I was able to restrict my domain to finite set of subjects and relations. I found Stanford's typed dependencies incredibly useful, they might help you too (to find those from smth relations).