CREATE TABLE flight(
	flno number(4,0) primary key,
	origin varchar2(20),
	destination varchar2(20),
	distance number(6,0),
	departure_date date,
	arrival_date date,
	price number(7,2),
    aid number(9,0),
    foreign key("aid") references `aircraft`("aid"))

CREATE TABLE aircraft(
	aid number(9,0) primary key,
	name varchar2(30),
	distance number(6,0))

CREATE TABLE employee(
	eid number(9,0) primary key,
	name varchar2(30),
	salary number(10,2))

CREATE TABLE certificate(
	eid number(9,0),
	aid number(9,0),
	primary key(eid,aid),
	foreign key("eid") references `employee`("eid"),
	foreign key("aid") references `aircraft`("aid"))
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"
Show names for all employees who do not have certificate of Boeing 737-800.