Database: flight_1
Question: What are the names of all employees who are not certified to fly Boeing 737-800s?
SQL: select name from employee except select t1.name from employee as t1 join certificate as t2 on t1.eid  =  t2.eid join aircraft as t3 on t3.aid  =  t2.aid where t3.name  =  "boeing 737-800"