SQL server--triggers

Trigger

A special stored procedure, can not be called directly, but by adding and deleting the action to trigger, a table of an action can only have a trigger

CREATE TABLE Users

(

IDS int primary key identity (.),

Name nvarchar (10),

Class nvarchar (10),

)

CREATE TABLE Class

(

Class_code nvarchar (Ten) primary key,

Class_name nvarchar (10),

)

Delete from users where Ids=1

Method 1:

Create Trigger user_delete--which action for which table

On users-- triggers for which table

for delete-- trigger for which action

As

SELECT * from users-- after which action to perform the replacement

Method 2:

Create Trigger Users1_delete

On users

instead of Delete

As

SELECT * from Users

SELECT * from deleted

declare @a nvarchar (10);

Select @a=ids from deleted;

If @a>5

Begin

Select ' is too ugly to erase '

End

Else

Begin

Delete from users where [email protected]

End

SQL server--triggers