QUESTION NO: 99
Which three are true regarding the use of outer joins? (Choose three.)
A. You cannot use IN operator in a condition that involves an outerjoin.
B. You use (+) on both sides of the WHERE condition to perform anouterjoin.
C. You use (*) on both sides of the WHERE condition to perform an outerjoin.
D. You use an outerjoin to see only the rows that do not meet the join condition.
E. In the WHERE condition, you use (+) following the name of the column in the table without matching rows, to perform an outerjoin.
F. You cannot link a condition that is involved in an outerjoin to another condition by using the OR operator.
Answer: D, E, F
QUESTION NO: 58
Examine the structure of the STUDENTS table:
STUDENT_ID
NUMBER NOT NULL, Primary Key
STUDENT_NAME VARCHAR2(30)
COURSE_ID
VARCHAR2(10) NOT NULL
MARKS
NUMBER
START_DATE DATE
FINISH_DATE DATE
You need to create a report of the 10 students who achieved the highest ranking in the course INT SQL and who completed the course in the year 1999.
Which SQL statement accomplishes this task?
A. SELECT student_ id, marks, ROWNUM "Rank" FROM students WHERE ROWNUM <= 10
AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99'
AND course_id = 'INT_SQL'
ORDER BY marks DESC;
B. SELECT student_id, marks, ROWID "Rank"
FROM students
WHERE ROWID <= 10
AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99'
AND course_id = 'INT_SQL'
ORDER BY marks;
C. SELECT student_id, marks, ROWNUM "Rank"
FROM (SELECT student_id, marks
FROM students
WHERE ROWNUM <= 10
AND finish_date BETWEEN '01-JAN-99' AND
'31-DEC-99'
AND course_id = 'INT_SQL'
ORDER BY marks DESC);
D. SELECT student_id, marks, ROWNUM "Rank:
FROM (SELECT student_id, marks
FROM students
ORDER BY marks)
WHERE ROWNUM <= 10
AND finish_date BETWEEN '01-JAN-99' AND '31-DEC-99'
AND course_id = 'INT_SQL';
Answer: D
感觉第一题的D不正确，而第二题没有正确答案。
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