text: CREATE TABLE Employee (eid VARCHAR); CREATE TABLE Certificate (eid VARCHAR) -- Show ids for all employees who don't have a certificate. SELECT eid FROM Employee EXCEPT SELECT eid FROM Certificate CREATE TABLE Aircraft (name VARCHAR, aid VARCHAR); CREATE TABLE Employee (eid VARCHAR, name VARCHAR); CREATE TABLE Certificate (eid VARCHAR, aid VARCHAR) -- Show names for all aircrafts of which John Williams has certificates. SELECT T3.name FROM Employee AS T1 JOIN Certificate AS T2 ON T1.eid = T2.eid JOIN Aircraft AS T3 ON T3.aid = T2.aid WHERE T1.name = "John Williams" CREATE TABLE Employee (name VARCHAR, eid VARCHAR); CREATE TABLE Certificate (eid VARCHAR, aid VARCHAR); CREATE TABLE Aircraft (aid VARCHAR, name VARCHAR) -- Show names for all employees who have certificate of Boeing 737-800. 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" CREATE TABLE Employee (name VARCHAR, eid VARCHAR); CREATE TABLE Certificate (eid VARCHAR, aid VARCHAR); CREATE TABLE Aircraft (aid VARCHAR, name VARCHAR) -- Show names for all employees who have certificates on both Boeing 737-800 and Airbus A340-300. 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" INTERSECT 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 = "Airbus A340-300"