Prolog - How to assert/make a database only once

Question

resultList(UsersQuery):-
    question(X,H),
    write(H),
    myintersection(H,UsersQuery,Match,TotalQuestionKeywords),
    Percent is Match/TotalQuestionKeywords*100,
          


        

Answer 1

Make a separate predicate for assertion that checks if fact is not yet asserted:

assertThisFact(Fact):-
    \+( Fact ),!,         % \+ is a NOT operator.
    assert(Fact).
assertThisFact(_).