doldrums
horse latitudes
trade winds
prevailing westerlies
第1题：
A. The DESCRIBE DEPT statement displays the structure of the DEPT table.
B. The ROLLBACK statement frees the storage space occupies by the DEPT table.
C. The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
D. The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.
第2题：
A.SELECT UNIQUE dept FROM staff
B.SELECT DISTINCT dept FROM staff
C.SELECT (dept) UNIQUE FROM staff
D.SELECT (dept) DISTINCT FROM staff
第3题：
设有关系模式：student(sno, sname, age, dept)，现利用命令： CREATE VIEW stu AS SELECT *FROM student WHERE dept="cs"WITH CHECK OPTION 创建了一个视图。则以下SQl命令中能正确执行的是
A．UPDATE stu SET dept="maths"
B．UPDATE stu SET dept="maths"WHERE age＞=20
C．INSERT INTO stu VALUES ("2004001", "John", 30, "cs")
D．INSERT INTO stu VALUES ("2004001", "John", 50, "maths")
第4题：
Which of the following statements eliminates all but one of each set of duplicate rows in the DEPT column in the STAFF table?（）
第5题：
A dead reckoning (DR) plot ______.
A.must utilize magnetic courses
B.must take set and drift into account
C.should be replotted hourly
D.should be started each time the vessel’s position is fixed
第6题：
A. The DESCRIBE DEPT statement displays the structure of the DEPT table.
B. The ROLLBACK statement frees the storage space occupies by the DEPT table.
C. The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
D. The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.
第7题：
设有关系模式：student(sno，sname，age，dept)，现利用命令： CREATE VIEW stu AS SELECT * FROM student WHERE dept="cs"WITH CHECK OPTION创建了一个视图。则以下SQL命令中能正确执行的是( )。
A．UPDATE stu SET dept="maths"
B．UPDATE stu SET dept="maths"WHERE age＞=20
C．INSERT INTO stu VALUES("2004001"，"John"，30，"CS")
D．INSERT INTO stu VALUES("200400l","John"，50，"maths")
第8题：
对于学生信息表：student(sno，sname，sex，age，dept)，如果把学生“小明”的姓名改为“小强”，则正确的语句是（ ）。
A)UPDATE SET sname=‘小明’WHERE sname=‘小强’
B)UPDATE student SET sname=‘小明’WHERE sname=‘小强’
C)UPDATE student SET sname=‘小强’
D)UPDATE student SET sname=‘小强’WHERE sname=‘小明’
第9题：
Evaluate the set of SQL statements: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set?（）
第10题：