Resolving the Error

To resolve the “Cannot insert explicit value for identity column” error, you need to ensure that the IDENTITY_INSERT option is appropriately configured for the target table. Here’s how to do it:

• Enable IDENTITY_INSERT Option
• Modify Insert Statement
• Check Table Constraints
• Verify Script Logic
• Check Database Configuration
• Debug Application Code
• Consider Alternatives

Consider the following example of the database:

1. Enable IDENTITY_INSERT Option

The primary approach to resolve this error is to enable the IDENTITY_INSERT option for the target table. This allows explicit values to be inserted into the identity column temporarily. The steps involved are:

• Use the following SQL command to enable the IDENTITY_INSERT option for the table:

SET IDENTITY_INSERT table_name ON;

• Execute the INSERT statement with explicit values for the identity column.
• After completing the insertion of explicit values, disable the IDENTITY_INSERT option using:

SET IDENTITY_INSERT table_name OFF;

Example:

Output Explanation: The SQL commands manage the identity column in the “EMPLOYEE” table. “SET IDENTITY_INSERT EMPLOYEE ON;” allows inserting specific values into the identity column. “INSERT INTO EMPLOYEE” adds a new record with specified values. “SET IDENTITY_INSERT EMPLOYEE OFF;” restores the default behavior of auto-generating identity column values.

2. Modify Insert Statement

If the intention is not to insert explicit values into the identity column, ensure that the INSERT statement does not specify a value for the identity column. Instead, allow SQL Server to generate the next identity value automatically. For example:

INSERT INTO table_name (column1, column2) VALUES (value1, value2);

Example:

Output Explanation: The output explanation details an attempt to insert values into the EMPLOYEE table, including an explicit value for the identity column, EMPLOYEEID. SQL Server rejects this due to identity column constraints. Resolution involves removing the explicit ID value or enabling IDENTITY_INSERT for the table before insertion.

3. Check Table Constraints

Review the table’s constraints and ensure that they are not preventing the insertion of explicit values into the identity column. Constraints such as DEFAULT constraints or CHECK constraints might be restricting the values that can be inserted into the column.

Example:

Output Explanation: The SQL statement sets a default constraint on the EMPLOYEEID column, auto-incrementing from 1. Attempting to insert a record directly into the EMPLOYEE table with a specified EMPLOYEEID value violates this constraint. Without enabling identity_insert, the system aborts the insertion, enforcing compliance with the constraint.

4. Verify Script Logic

If the error occurs within a script, carefully review the logic of the script to identify any instances where explicit values are being provided for the identity column unintentionally. Correct any scripting errors or oversights accordingly.

5. Check Database Configuration

Ensure that the database settings and configurations are correctly configured to allow the insertion of explicit values into identity columns when necessary. Check for any database-level settings or options that might be affecting the behavior of identity columns.

6. Debug Application Code

If the error is occurring within an application, debug the application code to identify the root cause of the issue. Ensure that the application is generating the INSERT statements correctly and handling identity columns appropriately.

7. Consider Alternatives

In some cases, it might be necessary to reconsider the approach to data manipulation and consider alternative methods for achieving the desired outcome without explicitly inserting values into identity columns. This might involve restructuring the database schema or redesigning the application logic.

In SQL, the error message “Cannot insert explicit value for identity column in table ‘table’ when IDENTITY_INSERT is set to OFF” is a common issue encountered when attempting to insert explicit values into an identity column in a table.

This error occurs because SQL, by default, does not allow explicit values to be inserted into identity columns unless the IDENTITY_INSERT option is explicitly set to ON for that table.In this article, we’ll delve into the causes of this error, how to resolve it, and best practices for working with identity columns in SQL.