query: SELECT CName FROM COURSE WHERE Credits  =  3 UNION SELECT CName FROM COURSE WHERE Credits  =  1 AND Hours  =  4
question: Find name course that have either 3 credit or 1 credits but 4 hour.
query_toks: SELECT CName FROM COURSE WHERE Credits = 3 UNION SELECT CName FROM COURSE WHERE Credits = 1 AND Hours = 4
query_toks_no_value: select cname from course where credits = value union select cname from course where credits = value and hours = value
question_toks: Find name course that have either 3 credit or 1 credits but 4 hour.