IPV4定义的IP地址长度为（） 。

A、32位

B、48位

C、64位

D、128位

You need to create a table named ORDERS that contain four columns: 1. an ORDER_ID column of number data type 2. aCUSTOMER_ID column of number data type 3. an ORDER_STATUS column that contains a character data type 4. aDATE_ORDERED column to contain the date the order was placed. When a row is inserted into the table, if no value is provided when the order was placed, today's date should be used instead. Which statement accomplishes this?（）

A、CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE = SYSDATE);

B、CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE DEFAULT SYSDATE);

C、CREATE OR REPLACE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE DEFAULT SYSDATE);

D、CREATE OR REPLACE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE = SYSDATE);

E、CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE = SYSDATE);

F、CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE DEFAULT SYSDATE);

Which two are attributes of iSQL*Plus? （）

iSQL*Plus commands cannot be abbreviated.

iSQL*Plus commands are accessed from a browser.

iSQL*Plus commands are used to manipulate data in tables.

iSQL*Plus commands manipulate table definitions in the database.

iSQL*Plus is the Oracle proprietary interface for executing SQL statements.

In which scenario would TOP N analysis be the best solution?（）

A、You want to identify the most senior employee in the company.

B、You want to find the manager supervising the largest number of employees.

C、You want to identify the person who makes the highest salary for all employees.

D、You want to rank the top three sales representatives who have sold the maximum number of products.

The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) The register has requested a report listing the students' grade point averages (GPA), sorted from highest grade point average to lowest within each semester, starting from the earliest date. Which statement accomplishes this?（）

A、SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester_end DESC, gpa DESC;

B、SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester _end, ASC,gpa ASC;

C、SELECT student_id, semester_end, gpa FROM student_grades ORDER BY semester _end, gpa DESC;

D、SELECT student_id, semester_end, gpa FROM student_grades ORDER BY gpa DESC,semester_end DESC;

E、SELECT student_id, semester_end, gpa FROM student_grades

Which SQL statement returns a numeric value?（）

A、SELECT ADD_MONTHS(MAX(hire_Date), 6) FROM EMP;

B、SELECT ROUND(hire_date) FROM EMP;

C、SELECT sysdate-hire_date FROM EMP;

D、SELECT TO_NUMBER(hire_date + 7) FROM EMP;