OCP-1Z0-新051-61题版本-13

QUESTION NO: 13

Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables:

Which MERGE statement is valid?

A.MERGE INTO new_employees c USING employees e ON (c.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE SET

name = e.first_name ||','|| e.last_name WHEN NOT MATCHED THEN INSERT value S(e.employee_id, e.first_name ||', '||e.last_name);

B.MERGE new_employees c USING employees e ON (c.employee_id = e.employee_id) WHEN EXISTS THEN UPDATE SET

name = e.first_name ||','|| e.last_name WHEN NOT MATCHED THEN INSERT valueS(e.employee_id, e.first_name ||', '||e.last_name);

C. MERGE INTO new_employees c USING employees e ON (c.employee_id = e.employee_id) WHEN EXISTS THEN UPDATE SET

. name = e.first_name ||','|| e.last_name WHEN NOT MATCHED THEN INSERT value S(e.employee_id, e.first_name ||',

'||e.last_name);

D.MERGE new_employees c FROM employees e ON (c.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE SET

. name = e.first_name ||','|| e.last_name WHEN NOT MATCHED THEN INSERT INTO new_employees valueS(e.employee_id, e.first_name ||', '||e.last_name);

Answer: A

答案解析：

参考：此题考MERGE的语法

Examples
Merging into a Table: Example The following example uses the

bonuses

table in the sample schema

oe

with
a default bonus of 100. It then inserts into the

bonuses

table all employees who made sales, based on the

sales_rep_id

column of the

oe.orders

table. Finally, the human resources manager decides that employees with a salary
of $8000 or less should receive a bonus. Those who have not made sales get a bonus of 1% of their salary. Those who already made sales get an increase in their bonus equal to 1% of their salary. The

MERGE

statement implements these changes in
one step:

CREATE TABLE bonuses (employee_id NUMBER, bonus NUMBER DEFAULT 100);

INSERT INTO bonuses(employee_id)
(SELECT e.employee_id FROM employees e, orders o
WHERE e.employee_id = o.sales_rep_id
GROUP BY e.employee_id);

SELECT * FROM bonuses ORDER BY employee_id;

EMPLOYEE_ID BONUS
----------- ----------
153 100
154 100
155 100
156 100
158 100
159 100
160 100
161 100
163 100

MERGE INTO bonuses D
USING (SELECT employee_id, salary, department_id FROM employees
WHERE department_id = 80) S
ON (D.employee_id = S.employee_id)
WHEN MATCHED THEN UPDATE SET D.bonus = D.bonus + S.salary*.01
DELETE WHERE (S.salary > 8000)
WHEN NOT MATCHED THEN INSERT (D.employee_id, D.bonus)
VALUES (S.employee_id, S.salary*.01)
WHERE (S.salary <= 8000);

SELECT * FROM bonuses ORDER BY employee_id;

EMPLOYEE_ID BONUS
----------- ----------
153 180
154 175
155 170
159 180
160 175
161 170
164 72
165 68
166 64
167 62
171 74
172 73
173 61
179 62

Explanation: Explanation: this is the correct MERGE statement syntax

Incorrect answer:

Bit should MERGE INTO table_name

Cit should be WHEN MATCHED THEN

Dit should MERGE INTO table_name

Refer: Introduction to Oracle9i: SQL, Oracle University Study Guide, 8-29