Magic Table in SQL Server
Magic Table:
In SQL server magic table is nothing more than an internal table which is created by the SQL server to recover recently inserted, deleted and updated data into SQL server database. That is when we insert or delete any record from any table in SQL server then recently inserted or deleted data from table also inserted into inserted magic table or deleted magic table with help of which we can recover data which is recently used to modify data into table either use in delete, insert or update to table. Basically there are two types of magic table in SQL server namely: inserted and deleted, update can be performed with help of these twos. Generally we cannot see these two table, we can only see it with the help Trigger’s in SQL server. Let’s see the following example:
INSERTED Magic Table:
When we insert record into table then SQL server automatically created ‘inserted’ magic table and recently inserted record are available in this table,If we want to recover this data which are recently inserted then we can access this record with the help of Trigger’s. Let’s see the demonstration of inserted magic table in SQL Server.
Example:
--- CREATE TABLE TO DEMONSTRATION OF INSERT MAGIC TABLE ----
CREATE TABLE INSERT_MAGIC
(
ID INT,
TRIGGER_MESSAGE VARCHAR(50)
)
-------DEMONSTRATION OF CREATING TRIGGER TO EXPLORE INSERTED MAGIC TABLE
CREATETRIGGER TRI_MAGIC_INSERT
ON USERLOGIN
INSTEADOFINSERT
AS
BEGIN
DECLARE @ID INT
SELECT @ID =(SELECT ID FROM inserted)
INSERTINTO INSERT_MAGIC VALUES (@ID,'RECORD ADDED')
END
GO
Note: Here ‘inserted’ is insert magic table
DELETED Magic Table:
When we delete record from the table then SQL automatically create a deleted magic table which holds are deleted record from original table if we want to recover it then we can access that data from deleted magic table. Let’s see demonstration of recover data from deleted magic table.
Example: Creating Trigger for Deleted Magic table
-------DEMONSTRATION OF CREATING TRIGGER TO EXPLORE INSERTED MAGIC TABLE
CREATETRIGGER TRI_MAGIC_DELETE
ON USERLOGIN
INSTEADOFINSERT
AS
BEGIN
DECLARE @ID INT
DECLARE @NAME VARCHAR(50)
SELECT @ID =(SELECT ID FROM deleted)
SELECT @NAME =(SELECT NAME FROM deleted)
INSERTINTO INSERT_MAGIC VALUES (@ID,@NAME)
END
GO
Anonymous User
12-Mar-2019Thanks for sharing the information.
Saravanan N
19-Nov-2011Good post - precisely explained Inserted and Deleted Magic tables.
Thanks for you link back on my post,
http://www.codemile.com/sql-server/2011/02/14/magic-tables-in-sqlserver-inserted-table-and-deleted-table/