Why Does Entity Framework Throw an Error When Inserting into an Identity Column?

Troubleshooting Entity Framework Error: Identity Column Insertion

This issue occurs when Entity Framework (EF) encounters an attempt to explicitly set the value of an identity column in a database table. Identity columns are typically generated automatically by the database, and EF handles this process seamlessly by default.

In the example provided, the error is thrown while saving a new GroupMember entity. The database table has an identity column named Id, and the EF designer file also specifies StoreGeneratedPattern as Identity for this column. However, the code appears to be trying to manually insert a value of 0 for the Id property of the entity.

To resolve this issue, ensure that you are not attempting to explicitly set the value for identity columns. Instead, rely on the database to generate and assign values automatically.

If necessary, update your edmx file to reflect the correct properties of your table. Specifically, check if the IsDbGenerated attribute is set to true in the designer file for the identity column. If it's not, manually add this attribute to indicate that the database should handle value generation for this column.

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