This example creates a table with an identity column and shows how the SET IDENTITY_INSERT setting can be used to fill a gap in the identity values caused by a DELETE statement.
-- Create products table.
CREATE TABLE products (id int IDENTITY PRIMARY KEY, product varchar(40))
GO
-- Inserting values into products table.
INSERT INTO products (product) VALUES ('screwdriver')
INSERT INTO products (product) VALUES ('hammer')
INSERT INTO products (product) VALUES ('saw')
INSERT INTO products (product) VALUES ('shovel')
GO
-- Create a gap in the identity values.
DELETE products
WHERE product = 'saw'
GO
SELECT *
FROM products
GO
-- Attempt to insert an explicit ID value of 3;
-- should return a warning.
INSERT INTO products (id, product) VALUES(3, 'garden shovel')
GO
-- SET IDENTITY_INSERT to ON.
SET IDENTITY_INSERT products ON
GO
-- Attempt to insert an explicit ID value of 3
INSERT INTO products (id, product) VALUES(3, 'garden shovel').
GO
SELECT *
FROM products
GO
-- Drop products table.
DROP TABLE products
GO