When and How Should You Use SQL Server's IDENTITY_INSERT?

Detailed explanation of IDENTITY_INSERT in SQL Server 2008

In SQL Server, IDENTITY_INSERT is a key setting that determines whether the database accepts explicit values ​​for identity columns. When set to OFF, the database automatically generates values ​​for these columns during INSERT operations. But in some cases, it may be necessary to set IDENTITY_INSERT to ON to insert the value manually.

Why disable and enable IDENTITY_INSERT?

A common reason to disable IDENTITY_INSERT is to enforce data integrity. By preventing explicit value insertion, the database ensures that consecutive ID values ​​are generated, thereby reducing the risk of duplicate entries. However, for some specific tasks, such as importing data from external sources, you may need to manually assign identity values.

Enable IDENTITY_INSERT using SQL query

To enable IDENTITY_INSERT in SQL Server 2008, execute the following query:

<code class="language-sql">SET IDENTITY_INSERT Database.dbo.Baskets ON</code>

Replace "Database" and "dbo" with the corresponding database and schema names. After executing this query, you can proceed with manual insertion.

Handling enabled IDENTITY_INSERT in code

Even if using queries is enabled IDENTITY_INSERT, if you still receive an error during an INSERT operation, it may be due to application code. Make sure your code does not attempt to set the identity column explicitly. When IDENTITY_INSERT is set to OFF, the database automatically assigns values ​​regardless of explicit values ​​specified in the code.

Remember, after completing manual insertion, be sure to return IDENTITY_INSERT to OFF to restore data integrity. Disable it using the following query:

<code class="language-sql">SET IDENTITY_INSERT Database.dbo.Baskets OFF</code>

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