學習筆記專區

SELECT *

INTO  copy_emp

FROM  employees

WHERE 1=2;

select * from copy_emp;

MERGE INTO copy_emp c

     USING employees e

     ON (c.employee_id = e.employee_id)

   WHEN MATCHED THEN

     UPDATE SET

       c.first_name     = e.first_name,

       c.last_name      = e.last_name,

       c.email          = e.email,

       c.phone_number   = e.phone_number,

       c.hire_date      = e.hire_date,

       c.job_id         = e.job_id,

       c.salary         = e.salary,

       c.commission_pct = e.commission_pct,

       c.manager_id     = e.manager_id,

       c.department_id  = e.department_id

   WHEN NOT MATCHED THEN

     INSERT VALUES(e.employee_id, e.first_name, e.last_name,

          e.email, e.phone_number, e.hire_date, e.job_id,

          e.salary, e.commission_pct, e.manager_id,

          e.department_id);--如果發現copy_emp中沒有employees裡有的欄位，則直接新增加入

select * from copy_emp;

--EMPLOYEES新增一筆時, 使用 MERGE會(就是上面那一大串)則 copy_emp也會新增一筆