Output clause in SQL Server

Level: Beginners [level 100]

Output   clause gives access to Inserted, updated or deleted rows of table. In SQL Server 2005 this was possible only through Triggers.

Note: In all explanation, I am going to use School Database. You can download script from here

Imagine a scenario that while inserting a value in Person table, for the audit purpose you need to insert value FirstName column and insertion date in audit table. This was possible in SQL Server through Triggers. Whereas in SQL Server 2008 we can achieve this using Output clause 

I created a table called Audit_Person in school database.

Now while inserting in Person table, I need to insert a row in this table also.

In above statement if you notice we are fetching inserted first name using Inserted.FirstName and current date using GetDate and inserting in Audit_Person table.

Let us say you have another scenario in which

1. You want to delete all the person First Name started with P
2. Insert First Name of deleted row with deleted date in Audit_Person table

To write above query you can use Output clause.

Scripts used in above explanation are below. Feel free to use them 

Create  table Audit_Person
         (PersonName nvarchar(max),
          DateOfEntry date);

Insert into Person(LastName ,FirstName)
    Output Inserted.FirstName,
           GetDate()
    into Audit_Person
    values
		('Dave','Pinal');

Delete from Person
  Output deleted.Firstname ,
          GetDate()
   Into audit_person
 where FirstName like 'P%';

I hope this post was useful. Thanks for reading