单项选择题

Evaluate these two SQL statements:
SELECT last_name, salary , hire_date
FROM EMPLOYEES
ORDER BY salary DESC;
SELECT last_name, salary, hire_date
FROM EMPLOYEES
ORDER BY 2 DESC;
What is true about them?()

A. The two statements produce identical results.
B. The second statement returns a syntax error.
C. There is no need to specify DESC because the results are sorted in descending order by default.
D. The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.


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2.单项选择题

The EMP table has these columns:
ENAME VARCHAR2(35)
SALARY NUMBER(8,2)
HIRE_DATE DATE
Management wants a list of names of employees who have been with the company for more than five years.
Which SQL statement displays the required results?()

A. SELECT ENAME FROM EMP WHERE SYSDATE-HIRE_DATE >5;
B. SELECT ENAME FROM EMP WHERE HIRE_DATE-SYSDATE >5;
C. SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)/365 >5;
D. SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)*/365 >5;

3.单项选择题What is necessary for your query on an existing view to execute successfully?()

A. The underlying tables must have data.
B. You need SELECT privileges on the view.
C. The underlying tables must be in the same schema.
D. You need SELECT privileges only on the underlying tables.

4.多项选择题Which two statements accurately describe a role? ()

A. A role can be given to a maximum of 1000 users.
B. A user can have access to a maximum of 10 roles.
C. A role can have a maximum of 100 privileges contained in it.
D. Privileges are given to a role by using the CREATE ROLE statement.
E. A role is a named group of related privileges that can be granted to the user.
F. A user can have access to several roles, and several users can be assigned the same role.

6.单项选择题In which case would you use a FULL OUTER JOIN?()

A. Both tables have NULL values.
B. You want all unmatched data from one table.
C. You want all matched data from both tables.
D. You want all unmatched data from both tables.
E. One of the tables has more data than the other.
F. You want all matched and unmatched data from only one table.

8.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.

9.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);

10.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;