在sql server 2005中，觸發器可以分為兩大類：dml觸發器和ddl觸發器
dml觸發器：dml觸發器是當資料庫伺服器中發生資料操作語言（data manipulation language）事件時執行的儲存過程。dml觸發器又分為兩類：after觸發器和instead of觸發器
ddl觸發器：ddl觸發器是在響應資料定義語言（data definition language）事件時執行的儲存過程。ddl觸發器一般用於執行資料庫中管理任務。如審核和規範資料庫操作、防止資料庫表結構被修改等。
dml觸發器的分類
sql server 2005的dml觸發器分為兩類：
after觸發器：這類觸發器是在記錄已經改變完之後（after），才會被啟用執行，它主要是用於記錄變更後的處理或檢查，一旦發現錯誤，也可以用rollback transaction語句來回滾本次的操作。
instead of觸發器：這類觸發器一般是用來取代原本的操作，在記錄變更之前發生的，它並不去執行原來sql語句裡的操作（insert、update、delete），而去執行觸發器本身所定義的操作
create
table employees(
employee_id int
primary
keynot
null,
last_name varchar
(50)
null,
first_name varchar
(50)
null,
hire_date datetime
null,
job_id int
null,
email varchar
(500)
null,
department_id int
null,
salary int
null,
commission_pct int
null)
create
trigger employees_update
on employees
after update
asbegin
'有乙個員工更改了'
endcreate
trigger employees_insert
on employees
after insert
asbegin
'有乙個員工增加了'
endcreate
trigger employees_delete
on employees
after delete
asbegin
'有乙個員工刪除了'
end
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values
(12345,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
delete
employees
update
employees set last_name =
'dabing'
where employee_id=12345;
select
*from employees
select
commission_pct from employees where employee_id=12345;
drop
trigger employees_insert
create
trigger employees_insert
on employees
after insertas
begin
declare @employee_id int
set @employee_id =
(select employee_id from inserted)
if(@employee_id > 5 )
begin
'員工號大於的不能新增'
rollback
transaction
endend;
alter
trigger employees_insert
on employees
instead
ofinsertas
begin
declare @employee_id int
set @employee_id =
(select employee_id from inserted)
if(@employee_id > 5 )
begin
'員工號大於的不能新增'
endend;
drop
trigger employees_delete
create
trigger employees_delete
on employees
instead
ofdeleteas
begin
declare @employee_id int
set @employee_id =
(select employee_id from deleted)
if(@employee_id > 2 )
begin
'員工號大於的不能刪除'
endend;
delete
employees where employee_id =
'3'
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values(1,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values(2,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values(3,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values(4,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values(5,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
insert
into employees(employee_id,last_name,first_name,hire_date,job_id,email,department_id,salary,commission_pct )
values(6,
'chen'
,'donny'
,'2010-05-08'
, 12,
,60,10000,25);
select
*from employees
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