OCP-1Z0-051 補充題庫 第13題 MERGE INTO語句

一、原題

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);

答案: A

二、題目翻譯

下面是EMPLOYEES和NEW_EMPLOYEES表的結構:

哪一個merge語句是有效的?

三、題目解析

A選項正确。

B選項和D選項不正确，merge into文法不正确，into關鍵字都沒有。

C選項不正确，文法錯誤，WHEN EXISTS THEN，應該是 WHEN MATCHED THEN。