SQL Identity_Insert 4

SQL IDENTITY INSERT

How to insert values into Identity Column using SQL IDENTITY INSERT with example. For this, We are going to use the below-shown Customer table inside the Database.

From the below code snippet, you can observe that the [Customer Key] column is an Identity column. And our job is to insert values into this identity column [Customer Key], i.e., SQL identity insert.

CREATE TABLE [Customer]
(
  [CustomerKey] [int] IDENTITY(1,1) NOT NULL,
  [FirstName] [varchar](50) NULL,
  [LastName] [varchar](50) NULL,
  [BirthDate] [date] NULL,
  [EmailAddress] [nvarchar](50) NULL,
  [Yearly Income] [money] NULL,
  [Profession] [nvarchar](100) NULL
)

Insert values into the Identity Column

Before we start using the SQL IDENTITY INSERT Command, Let us see what will happen when we insert values into Identity Column (Customer Key) using the following statement

INSERT INTO [Customer] 
  ([CustomerKey], [FirstName],[LastName],[BirthDate],[EmailAddress],[Yearly Income],[Profession])
VALUES (1, 'John', 'Miller', '2006-01-28', 
        'sql@tutorialgateway.org', 20000, 'Developer')

Run the above query to insert value into identity column

Messages
--------
Msg 544, Level 16, State 1, Line 2
Cannot insert explicit value for identity column in table 'Customer' when IDENTITY_INSERT is set to OFF.

From the above screenshot, you can observe that it is throwing an error saying: Cannot insert explicit value for identity column in table ‘Customer’ when IDENTITY_INSERT is set OFF. It is because any Column using an IDENTITY property will start based on the starting position and automatically increments based on increment value for each row inserted into the table.

Let us see, What will happen when we insert remaining values apart from the identity column (customer key) in SQL Server.

-- Identity Insert Example
INSERT INTO [Customer] 
  ([FirstName],[LastName],[BirthDate],
   [EmailAddress],[Yearly Income],[Profession])
VALUES ('John', 'Miller', '2006-01-28', 
        'sql@tutorialgateway.org', 20000, 'Developer')
Messages
--------
(1 row(s) affected)

From the above screenshot, you can observe that 1 row affected. Now, let us see, whether the above statement is inserted the values into the Customer table or not by using the following SQL Query

SELECT * FROM [Customer]

From the below, you can observe that Customer Key value 1 automatically inserted because of the IDENTITY.

SQL IDENTITY INSERT 3

SET IDENTITY_INSERT ON / OFF

In this example, We will use the SQL SET IDENTITY_INSERT property to set the IDENTITY of a column to ON and OFF

--  Identity Insert Example
SET IDENTITY_INSERT [Customer] ON  

INSERT INTO [Customer] 
  ([CustomerKey], [FirstName],[LastName],[BirthDate],
   [EmailAddress],[Yearly Income],[Profession])
VALUES (100, 'Tutorial', 'Gateway', '2015-08-31', 
         'contact@tutorialgateway.org', 50000, 'Founder')

SET IDENTITY_INSERT [Customer] OFF
SQL IDENTITY INSERT 4

The following statement will set the SQL Identity Insert ON on the Customers table.

SET IDENTITY_INSERT [Customer] ON

The below statement will insert the explicit values into the Customer table. It includes IDENTITY Column [Customer Key]

INSERT INTO [Customer] 
  ([CustomerKey], [FirstName],[LastName],[BirthDate],
   [EmailAddress],[Yearly Income],[Profession])
VALUES (100, 'Tutorial', 'Gateway', '2015-08-31', 
         'contact@tutorialgateway.org', 50000, 'Founder')

The following statement will set the Identity_Insert OFF on the Customers table. Remember, after this statement; you can’t insert values into Identity column (Here, [Customer Key])

SET IDENTITY_INSERT [Customer] OFF

Use the below query to check whether the above statement is inserted the values into the Identity Column or not

SELECT * FROM [Customer]

You can see that we successfully inserted the values into the identity column.

SQL IDENTITY INSERT 5

A session allows only one table to set it’s IDENTITY_INSERT property ON. If you try to issues SET IDENTITY_INSERT ON statement on multiple tables, SQL returns an error message

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