多项选择题
Examine the description of the STUDENTS table:
STD_ID NUMBER(4)
COURSE_ID VARCHAR2(10)
START_DATE DATE
END_DATE DATE
Which two aggregate functions are valid on the START_DATE column? ()
A.SUM（start_date）
B.AVG（start_date）
C.COUNT（start_date）
D.AVG（start_date，end_date）
E.MIN（start_date）
F.MAXIMUM（start_date）
相关考题
-
单项选择题
Examine this statement: SELECT student_id, gpa FROM student_grades WHERE gpa > &&value; You run the statement once, and when prompted you enter a value of 2.0. A report is produced. What happens when you run the statement a second time?（）
A.An error is returned.
B.You are prompted to enter a new value.
C.A report is produced that matches the first report produced.
D.You are asked whether you want a new value or if you want to run the report based on the previous value. -
单项选择题
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?（）
A.The DESCRIBE DEPT statement displays the structure of the DEPT table.
B.The ROLLBACK statement frees the storage space occupied 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. -
单项选择题
Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMPLOYEE_ID NUMBER DEPARTMENT_ID NUMBER MANAGER_ID NUMBER LAST_NAME VARCHAR2(25) DEPARTMENTS DEPARTMENT_ID NUMBER MANAGER_ID NUMBER DEPARTMENT_NAME VARCHAR2(35) LOCATION_ID NUMBER You want to create a report displaying employee last names, department names, and locations. Which query should you use?（）
A.SELECT e.last_name, d. department_name, d.location_id FROM employees e NATURAL JOIN departments D USING department_id ;
B.SELECT last_name, department_name, location_id FROM employees NATURAL JOIN departments WHERE e.department_id =d.department_id;
C.SELECT e.last_name, d.department_name, d.location_id FROM employees e NATURAL JOIN departments d;
D.SELECT e.last_name, d.department_name, d.location_id FROM employees e JOIN departments d USING (department_id );
