SQL>
SQL>
SQL> CREATE TABLE emp (
2 empID INT NOT NULL PRIMARY KEY,
3 Name VARCHAR(50) NOT NULL);
Table created.
SQL> INSERT INTO emp (empID,Name) VALUES (1,'Tom');
1 row created.
SQL> INSERT INTO emp (empID,Name) VALUES (2,'Jack');
1 row created.
SQL> INSERT INTO emp (empID,Name) VALUES (3,'Mary');
1 row created.
SQL> INSERT INTO emp (empID,Name) VALUES (4,'Bill');
1 row created.
SQL> INSERT INTO emp (empID,Name) VALUES (5,'Cat');
1 row created.
SQL> INSERT INTO emp (empID,Name) VALUES (6,'Victor');
1 row created.
SQL> CREATE TABLE empExam (
2 empID INT NOT NULL,
3 ExamID INT NOT NULL,
4 Mark INT,
5 IfPassed SMALLINT,
6 Comments VARCHAR(255),
7 CONSTRAINT PK_empExam PRIMARY KEY (empID, ExamID));
Table created.
SQL>
SQL>
SQL> INSERT INTO empExam (empID,ExamID,Mark,IfPassed,Comments) VALUES (1,1,55,1,'Satisfactory');
1 row created.
SQL> INSERT INTO empExam (empID,ExamID,Mark,IfPassed,Comments) VALUES (1,2,73,1,'Good result');
1 row created.
SQL> INSERT INTO empExam (empID,ExamID,Mark,IfPassed,Comments) VALUES (2,3,44,1,'Hard');
1 row created.
SQL> INSERT INTO empExam (empID,ExamID,Mark,IfPassed,Comments) VALUES (2,5,39,0,'Simple');
1 row created.
SQL> INSERT INTO empExam (empID,ExamID,Mark,IfPassed) VALUES (2,6,63,1);
1 row created.
SQL>
SQL>
SQL>
SQL> SELECT empID, Name,
2 (SELECT COUNT(*) FROM empExam
3 WHERE empExam.empID = emp.empID)
4 AS ExamsTaken
5 FROM emp
6 ORDER BY ExamsTaken DESC;
EMPID NAME EXAMSTAKEN
---------- -------------------------------------------------- ----------
2 Jack 3
1 Tom 2
5 Cat 0
4 Bill 0
6 Victor 0
3 Mary 0
6 rows selected.
SQL>
SQL> drop table empExam;
Table dropped.
SQL> drop table emp;
Table dropped.