How to Create Triggers in sql server 2008

What is a trigger?
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                Trigger is a Special kind of Stored Procedure that is invoked whenever an
Attempt is made to modify the data in the table the trigger will protects

                 A table Can have three trigger actions :
                        1.Update,
                        2.Insert,
                        3.Delete

Only Table owners can create and drop triggers for the table.Trigger is Attached to a table or View
and is fired only when an Insert,Update,Delete Occurs,While stored procedure executes at any time
while is is called.

     Triggers are Mainly divided in to Two Categories:

      1. After trigger(FOR trigger) -----(AFTER INSERT,AFTER UPDATE,AFTER DELETE)
      2. Instead of Triggers


A simple Syntax For triggers:
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             Create Trigger Trigger_Name
             ON (Table or view)
             AFTER Insert,Update,Delete
             AS
           
               DECLARE
                 //initialize parameters if any required like (@Empid int;) //
             
             BEGIN


               // Insert ,Update ,Delete Stamt....//
                 
              PRINT('AFTER InSERT TRIGGER FIRED')
            
              END
               GO

Trigger Example For After Insert Trigger:
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         First Create a Table With the Name product Having the columns like Below

        Create Table Product
        (
          Product_id int,
          productName varchar(50),
          Address varchar(50)
        )
        





Trigger for After Insert :
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                    CREATE  TRIGGER Product_trigger
                    ON  dbo.Product
                    AFTER INSERT
                    AS
                    DECLARE
                    @Product_id int,
                    @productName varchar(50),
                    @Address varchar(50)
                    BEGIN
                Insert into  Product (Product_id,ProductName,Address)values(@Product_id,@ProductName,@Address)

                    END
                    GO


                 In the Above dbo.Product is a table Name And  Product_trigger is Trigger Name.


How to Eanble/Disable Trigger Associated Table:
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           Alter Table Table_Name  ENABLE/DISABLE Trigger ALL   -----(It is For All Tables In a Data Base)


            Alter Table Table_Name ENABLE/DISABLE Trigger Trigger_Name ( It is only For A Particuler
                                                                           Trigger Assosiated Table )



              Ex: Alter Table Product ENABLE Trigger Product_trigger


Difference Between AFTER TRIGGERS AND INSTEAD TRIGGERS :
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    1.  Instead Triggers Only single Implementation is possible on table .Where as After Triggers Support a multiple triggers to a single Table
  
    2. Insted Triggers Applied on View .where As After Triggers Cant be Applied on View.