SQL>
SQL> CREATE TABLE emp (
2 empID INT NOT NULL PRIMARY KEY,
3 CourseID INT NOT NULL,
4 ProfessorID INT NOT NULL,
5 SustainedOn DATE,
6 Comments VARCHAR(255));
Table created.
SQL> INSERT INTO emp (empID,CourseID,ProfessorID,SustainedOn,Comments) VALUES (1,1,1,DATE '2003-03-12','Hard');
1 row created.
SQL> INSERT INTO emp (empID,CourseID,ProfessorID,SustainedOn,Comments) VALUES (2,2,1,DATE '2003-03-13','Simple');
1 row created.
SQL> INSERT INTO emp (empID,CourseID,ProfessorID,SustainedOn,Comments) VALUES (3,3,2,DATE '2003-03-11','1 hour long');
1 row created.
SQL> INSERT INTO emp (empID,CourseID,ProfessorID,SustainedOn) VALUES (4,4,3,DATE '2003-03-18');
1 row created.
SQL>
SQL> SELECT empID, SustainedOn FROM emp
2 WHERE SustainedOn <= (
3 SELECT SustainedOn FROM emp WHERE empID = 5)
4 ORDER BY SustainedOn DESC;
no rows selected
SQL>
SQL> drop table emp;
Table dropped.