Migrating a Project from Another Data Source

Some developers start their ADO.NET Entity Framework projects with Microsoft SQL Server, and then migrate the projects to an enterprise-wide data source such as DB2. While this practice might seem to be convenient, the migration cost can be expensive.

Data sources such as Microsoft SQL Server include boolean types. Porting applications to a data source that does not support boolean types could incur an unacceptable overhead. For example, meticulous and error-prone editing of Entity Framework mapping files could be required.

The DB2 Entity Framework data provider defines data types to facilitate the migration to DB2. These data types are designed to support data types at the Entity Framework conceptual layer in terms of how they will be described at the data source layer.

Because DB2 does not have a formal Boolean or Byte type, two data types have been defined to follow the conventions understood by DB2-based applications. The smallint_as_boolean and the smallint_as_byte SSDL data types indicate the relative mapping from the context of the DB2 data source.

Similarly, the DB2 Timestamp does not map directly to the Entity Framework DateTimeOffset data type. The timestamp_as_datetimeoffset SSDL data type has been defined to ensure that the value can be successfully round-tripped to the database.