Which two statements about subqueries ...

多项选择题Which two statements about subqueries are true?（）

A. A single row subquery can retrieve data from only one table.
B. A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.
C. A SQL query statement can display data from table B that is referred to in its subquery, without including table B in its own FROM clause.
D. A single row subquery can retrieve data from more than one table.
E. A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.
F. A multiple-row subquery cannot be used in a condition where the LIKE operator is used for comparison.

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1.单项选择题 Examine the data in the EMPLOYEES and EMP_HIST tables:
EMPLOYEES
NAME DEPT_ID MGR_ID JOB_ID SALARY
EMPLOYEE_ID
101 Smith 20 120 SA_REP 4000
102 Martin 10 105 CLERK 2500
103 Chris 20 120 IT_ADMIN 4200
104 John 30 108 HR_CLERK 2500
105 Diana 30 108 IT_ADMIN 5000
106 Smith 40 110 AD_ASST 3000
108 Jennifer 30 110 HR_DIR 6500
110 Bob 40 EX_DIR 8000
120 Ravi 20 110 SA_DIR 6500
EMP HIST
EMPLOYEE_ID NAME JOB_ID SALARY
101 Smith SA_CLERK 2000
103 Chris IT_CLERK 2200
104 John HR_CLERK 2000
106 Smith AD_ASST 3000
108 Jennifer HR_MGR 4500
The EMP_HIST table is updated at the end of every year. The employee ID, name, job ID, and salary of each existing employee are modified with the latest data. New employee details are added to the table.
Which statement accomplishes this task?（）

A. UPDATE emp_hist SET employee_id, name, job_id, salary = (SELECT employee_id, name, job_id, salary FROM employees) WHERE employee_id IN (SELECT employee_id FROM employees);
B. MERGE INTO emp_hist eh USING employees e ON (eh.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT VALUES (e.employee id, e.name, job id, e.salary);
C. MERGE INTO emp_hist eh USING employees e ON (eh.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE emp hist SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT INTO emp_hist VALUES (e.employees_id, e.name, e.job_id, e.salary);
D. MERGE INTO emp_hist eh USING employees e WHEN MATCHED THEN UPDATE emp_hist SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT INTO emp_hist VALUES (e.employees_id, e.name, e.job_id, e.salary);

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2.多项选择题Which three SELECT statements displays 2000 in the format “$2,000.00”?（）

A. SELECT TO CNAR(2000, ‘$#,###.##’)   FROM dual;
B. SELECT TO CNAR(2000, ‘$0,000.00’)   FROM dual;
C. SELECT TO CNAR(2000, ‘$9,999.00’)   FROM dual;
D. SELECT TO CNAR(2000, ‘$9,999.99’)   FROM dual;
E. SELECT TO CNAR(2000, ‘$2,000.00’)   FROM dual;
F. SELECT TO CNAR(2000, ‘$N,NNN.NN’)   FROM dual;

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3.多项选择题For which two constraints does the Oracle Server implicitly create a unique index?（）

A. NOT NULL
B. PRIMARY KEY
C. FOREIGN KEY
D. CHECK
E. UNIQUE

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4.单项选择题 You created a view called EMP_DEPT_VU that contains three columns from the EMPLOYEES and DEPARTMENTS tables:
EMPLOYEE_ID, EMPLOYEE_NAME AND DEPARTMENT_NAME.
The DEPARTMENT_ID column of the EMPLOYEES table is the foreign key to the primary key DEPARTMENT_ID column of the DEPARTMENTS table.
You want to modify the view by adding a fourth column, MANAGER_ID of NUMBER data type from the EMPLOYEES tables.
How can you accomplish this task?（）

A. ALTER VIEW emp_dept_vu (ADD manager_id NUMBER);
B. MODIFY VIEW emp_dept_vu (ADD manager_id NUMBER);
C. ALTER VIEW emp_dept_vu AS   SELECT employee_id, employee_name,   department_name, manager_id   FROM employee e, departments d   WHERE e.department_id = d.department_id;
D. MODIFY VIEW emp_dept_vu AS   SELECT employee_id, employee_name,   department_name, manager_id   FROM employees e, departments d   WHERE e.department_id = d.department_id;
E. CREATE OR REPLACE VIEW emp_dept_vu AS   SELECT employee_id, employee_name,   department_name, manager_id   FROM employees e, departments d   WHERE e.department_id = d.department_id;
F. You must remove the existing view first, and then run the CREATE VIEW command   with a new column list to modify a view.

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5.多项选择题 The ORDERS table has these columns:
ORDER_ID NUMBER(4) NOT NULL
CUSTOMER_ID NUMBER(12) NOT NULL
ORDER_TOTAL NUMBER(10,2)
The ORDERS table tracks the Order number, the order total, and the customer to whom the Order belongs. Which two statements retrieve orders with an inclusive total that ranges between 100.00 and 2000.00 dollars? （）

A. SELECT customer_id, order_id, order_total FROM orders RANGE ON order _ total (100 AND 2000) INCLUSIVE;
B. SELECT customer_id, order_id, order_total FROM orders HAVING order _ total BETWEEN 100 and 2000;
C. SELECT customer_id, order_id, order_total FROM orders WHERE order _ total BETWEEN 100 and 2000;
D. SELECT customer_id, order_id, order_total FROM orders WHERE order_total>= 100 and <= 2000;
E. SELECT customer_id, order_id, order_total FROM orders WHERE order_total>= 100 and order_total <= 2000;

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6.单项选择题 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

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7.单项选择题In a SELECT statement that includes a WHERE clause, where is the GROUP BY clause placed in the SELECT statement?（）

A. Immediately after the SELECT clause
B. Before the WHERE clause
C. Before the FROM clause
D. After the ORDER BY clause
E. After the WHERE clause

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8.多项选择题 Examine the SQL statements that creates ORDERS table:

For which columns would an index be automatically created when you execute the above SQL statement? （）

A. SER_NO
B. ORDER_ID
C. STATUS
D. PROD_ID
E. ORD_TOTAL
F. Composite index on ORDER_ID and ORDER_DATE

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9.单项选择题 Examine the data of the EMPLOYEES table.
EMPLOYEES (EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID)
EMP_NAME DEPT_ID MGR_ID JOB_ID SALARY
EMPLOYEE_ID
101 Smith 20 120 SA_REP 4000
102 Martin 10 105 CLERK 2500
103 Chris 20 120 IT_ADMIN 4200
104 John 30 108 HR_CLERK 2500
105 Diana 30 108 HR_MGR 5000
106 Bryan 40 110 AD_ASST 3000
108 Jennifer 30 110 HR_DIR 6500
110 Bob 40 EX_DIR 8000
120 Ravi 20 110 SA_DIR 6500
Which statement lists the ID, name, and salary of the employee, and the ID and name of the employee's manager, for all the employees who have a manager and earn more than 4000?（）

A. SELECT employee_id "Emp_id", emp_name "Employee", salary, employee_id "Mgr_id", emp_name "Manager" FROM employees WHERE salary > 4000;
B. SELECT e.employee_id "Emp_id", e.emp_name "Employee",
C. salary,
D. employee_id "Mgr_id", m.emp_name "Manager" FROM employees e, employees m WHERE e.mgr_id = m.mgr_id AND e.salary > 4000;

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10.单项选择题Which statement explicitly names a constraint?（）

A. ALTER TABLE student_grades   ADD   FOREIGN KEY (student_id) REFERENCES students(student_id);
B. ALTER TABLE student_grades   ADD CONSTRAINT NAME = student_id_fk   FOREIGN KEY (student_id) REFERENCES students(student_id);
C. ALTER TABLE student_grades   ADD CONSTRAINT student_id_fk   FOREIGN KEY (student_id) REFERENCES students(student_id);
D. ALTER TABLE student grades   ADD NAMED CONSTRAINT student_id_fk   FOREIGN KEY (student_id) REFERENCES students(student_id);
E. ALTER TABLE student grades   ADD NAME student_id_fk   FOREIGN KEY (student_id) REFERENCES students(student_id);

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