Why Can't I Insert a Value into My Identity Column and How Do I Fix It?

Troubleshooting Identity Column Inserts in SQL Server

Encountering issues inserting values into an identity column in SQL Server? This guide explains the common error and provides a straightforward solution.

The Problem:

Attempting to insert a row with a specified value for an identity column often results in the following error:

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

Understanding the Error:

Identity columns automatically generate unique sequential values. The error arises because IDENTITY_INSERT is, by default, set to OFF. This setting prevents direct assignment of values to identity columns, ensuring the database maintains control over the sequence.

The Solution:

To insert a specific value into an identity column, you need to temporarily override this default behavior. Follow these steps:

1. Enable IDENTITY_INSERT: Use this command to temporarily allow explicit value insertion:

SET IDENTITY_INSERT Table1 ON

2. Execute the INSERT statement: Now, insert your data. Crucially, you must specify all columns in the INSERT statement:

INSERT INTO Table1 (OperationID, OpDescription, FilterID)
VALUES (20, 'Hierarchy Update', 1)

3. Disable IDENTITY_INSERT: After the insertion, immediately disable IDENTITY_INSERT to restore the default behavior:

SET IDENTITY_INSERT Table1 OFF

This process allows you to manage identity column values under specific circumstances while maintaining data integrity. Remember to always disable IDENTITY_INSERT once the insertion is complete.

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