Why Does Entity Framework Throw an 'Cannot insert explicit value for identity column' Error?

Entity Framework Error: Inserting Explicit Value into Identity Column

When encountering the error "Cannot insert explicit value for identity column in table," it indicates that an attempt is being made to insert a specific value into an identity column that is automatically generated by the database.

In Entity Framework, this issue can arise when the database's identity increment column is set, but the StoreGeneratedPattern property in the EF design file is also set to identity. This causes EF to treat the column as a non-identity column, attempting to insert a value instead of relying on the database's auto-increment.

To resolve this issue, adjust either the database's identity increment settings or the EF design file's StoreGeneratedPattern property.

One suggestion is to ensure that the "IsDbGenerated=true" attribute is present in the EF designer file for the property corresponding to the identity column in the database. This indicates that the value should be database-generated.

Alternatively, if the database automatically assigns the value, you can update the edmx file to reflect this change. By updating the edmx file, you can specify that the column is database-generated and should not be assigned a specific value from the application code.

The above is the detailed content of Why Does Entity Framework Throw an 'Cannot insert explicit value for identity column' Error?. For more information, please follow other related articles on the PHP Chinese website!