This document details the steps required to provide Microsoft Entity Framework access to ODBC to ODBC Bridge Schema Objects using the
The following prerequisites must be in place for this solution to be possible.
An ODBC to ODBC Bridge DBMS hosting the required Schema Objects needs to be available. In this document the Microsoft Access Northwind sample database will be used to demonstrate the process.
An ODBC to ODBC Bridge Driver is required for linking the ODBC to ODBC Bridge Schema Objects into the Virtuoso Server.
The odbcma will be assumed to exist on the machine hosting the Virtuoso Server.
A Virtuoso installation including the Virtuoso Universal Server and ADO.NET Entity Framework Provider is required. The Virtuoso components used must be Release 5.10.x or above, this being the minimum version containing support for Microsoft Entity Frameworks.
Microsoft Visual Studio 2008 Service Pack 1 is required, this being the only version containing the necessary Entity Framework support available at the time of writing.
The Visual Studio 2008 Entity Data Model (EDM) requires that all primary keys are NOT Nullable. Visual Studio will fail to generate an EDM, if any are. Therefore, ensure that any primary keys to be used are defined as not nullable in the ODBC to ODBC Bridge database schema before attempting to generate an EDM.
The Virtuoso Virtual Database engine uses ODBC as the connectivity mechanism for linking remote database objects into its local schema.
Thus an ODBC to ODBC Bridge Driver must be available with a suitably configured DSN for connecting to the target database.
The
Installation instructions for the
Now that a Microsoft Entity Data Model has been created for the ODBC to ODBC Bridge database, Entity Framework applications can be created to make use of it.