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 thebonuses 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