/*
mysql> SELECT DISTINCT Mark FROM Exam;
+------+
| Mark |
+------+
| 55 |
| 73 |
| 44 |
+------+
3 rows in set (0.00 sec)
*/
/* Prepare the data */
Drop TABLE Exam;
CREATE TABLE Exam (
StudentID INT NOT NULL,
ExamID INT NOT NULL,
Mark INT,
IfPassed SMALLINT
)TYPE = InnoDB;
/* Insert data for testing */
INSERT INTO Exam (StudentID,ExamID,Mark,IfPassed) VALUES (1,1,55,1);
INSERT INTO Exam (StudentID,ExamID,Mark,IfPassed) VALUES (1,2,73,0);
INSERT INTO Exam (StudentID,ExamID,Mark,IfPassed) VALUES (2,3,44,1);
INSERT INTO Exam (StudentID,ExamID,Mark,IfPassed) VALUES (1,4,55,1);
INSERT INTO Exam (StudentID,ExamID,Mark,IfPassed) VALUES (1,5,73,0);
INSERT INTO Exam (StudentID,ExamID,Mark,IfPassed) VALUES (2,6,44,1);
/* Real command */
SELECT DISTINCT Mark FROM Exam;