databasegenerated

Database-generated refers to values produced by the database engine rather than by application code. Common examples include identity or auto-incremented primary keys, computed columns whose values are derived from other columns, and values produced by default constraints or triggers. The database is responsible for computing and returning these values when a row is inserted or updated.

In object-relational mappers such as Entity Framework, a property can be marked as database-generated to indicate that its value is not supplied by the application and should be read back after database operations. In EF6, this is expressed with the DatabaseGeneratedOption enumeration (Identity, Computed, None) via the DatabaseGeneratedAttribute. In EF Core, the same concept is available via the DatabaseGenerated attribute or Fluent API with configurations such as ValueGeneratedOnAdd, ValueGeneratedOnAddOrUpdate. A property configured as Identity typically has a value generated on insert; Computed means the value is generated on insert and on update; None means the application provides the value.

Typical use cases include a primary key column defined as an IDENTITY, a computed column such as TotalPrice defined as Quantity times UnitPrice, and a timestamp or rowversion column used for optimistic concurrency. When a property is database-generated, the ORM usually excludes it from INSERT or UPDATE statements and retrieves the value after the operation. Developers should ensure that the semantics match the database constraints and avoid attempting to assign values to such properties.