单项选择题

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);

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多项选择题Which four are attributes of single row functions? （）

A. cannot be nested
B. manipulate data items
C. act on each row returned
D. return one result per row
E. accept only one argument and return only one value
F. accept arguments which can be a column or an expression

单项选择题Which describes the default behavior when you create a table? （）

A. The table is accessible to all users.
B. Tables are created in the public schema.
C. Tables are created in your schema.
D. Tables are created in the DBA schema.
E. You must specify the schema when the table is created.

单项选择题The STUDENT_GRADES table has these columns: STUDENT_ID NUMBER(12) SEMESTER_END DATE GPA NUMBER(4,3) The registrar requested a report listing the students grade point averages (GPA) sorted from highest grade point average to lowest. Which statement produces a report that displays the student ID and GPA in the sorted order requested by the registrar? （）

A. SELECT student_id, gpa FROM student_grades ORDER BY gpa ASC;
B. SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa ASC;
C. SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa;
D. SELECT student_id, gpa FROM student_grades ORDER BY gpa;
E. SELECT student_id, gpa FROM student_grades SORT ORDER BY gpa DESC;
F. SELECT student_id, gpa FROM student_grades ORDER BY gpa DESC;

单项选择题You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task?（）

A. ALTER TABLE students ADD PRIMARY KEY _ id;
B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);
C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;
D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);

单项选择题You are the DBA for an academic database. You need to create a role that allows a group of users to modify existing rows in the STUDENT_GRADES table. Which set of statements accomplishes this? （）

A. CREATE ROLL registrar; GRANT MODIFY ON student_grant TO registrar; GRANT registrar to user 1, user2, user3
B. CREATE NEW ROLE registrar; GRANT ALL ON student_grant TO registrar; GRANT registrar to user 1, user2, user3
C. CREATE ROLL registrar; GRANT UPDATE ON student_grant TO registrar; GRANT ROLE to user1, user2, user3
D. CREATE ROLL registrar; GRANT UPDATE ON student_grant TO registrar; GRANT registrar to user 1, user2, user3;
E. CREATE registrar; GRANT CHANGE ON student_grant TO registrar; GRANT registrar;