ocp考试题库下载：11g-v9.02-051-122题
ocp考试题库下载：11g-v9.02-051-122题，完整题库请点击这里联系老师咨询了解
122. View the Exhibit for the structure of the STUDENT and FACULTY tables.
You need to display the faculty name followed by the number of students handled by the faculty at the
base location.
Examine the following two SQL statements:
Statement 1
SQL>SELECT faculty_name,COUNT(student_id)
FROM student JOIN faculty
USING (faculty_id, location_id)
GROUP BY faculty_name;
Statement 2
SQL>SELECT faculty_name,COUNT(student_id)
FROM student NATURAL JOIN faculty
GROUP BY faculty_name;
Which statement is true regarding the outcome?
A. Only s tatement 1 executes successfully and gives the required result.
B. Only statement 2 executes successfully and gives the required result.
C. Both statements 1 and 2 execute successfully and give different results.
D. Both statements 1 and 2 execute successfully and give the same required result.
Answer: D
试题解析：
当且仅当student表中的faculty_id列能隐式转换为数字类型时，这两个查询语句才可以查询成功。
因为NATURAL JOIN是将两个表中具有相同名称的所有列都连接起来，即FACULTY_ID和LOCATION_ID,而USING子句也使用了这两个字段来连接，故结果相同。
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