SET IDENTITY_INSERT table_name ON

Allows explicit values to be inserted into the identity column of a table.

Syntax:

SET IDENTITY_INSERT [ database_name . [ schema_name ] . ] table { ON | OFF }

e.g.:

USE AdventureWorks;

GO

-- Create tool table.

CREATE TABLE dbo.Tool(

   ID INT IDENTITY NOT NULL PRIMARY KEY, 

   Name VARCHAR(40) NOT NULL

)

GO

-- Inserting values into products table.

INSERT INTO dbo.Tool(Name) VALUES ('Screwdriver')

INSERT INTO dbo.Tool(Name) VALUES ('Hammer')

INSERT INTO dbo.Tool(Name) VALUES ('Saw')

INSERT INTO dbo.Tool(Name) VALUES ('Shovel')

GO



-- Create a gap in the identity values.

DELETE dbo.Tool 

WHERE Name = 'Saw'

GO



SELECT * 

FROM dbo.Tool

GO



-- Try to insert an explicit ID value of 3;

-- should return a warning.

INSERT INTO dbo.Tool (ID, Name) VALUES (3, 'Garden shovel')

GO

-- SET IDENTITY_INSERT to ON.

SET IDENTITY_INSERT dbo.Tool ON

GO



-- Try to insert an explicit ID value of 3.

INSERT INTO dbo.Tool (ID, Name) VALUES (3, 'Garden shovel')

GO



SELECT * 

FROM dbo.Tool

GO

-- Drop products table.

DROP TABLE dbo.Tool

GO