Using Microsoft Entity Frameworks to Access Oracle Schema Objects with Virtuoso
This document details the steps required to provide Microsoft Entity Framework access to Oracle Schema Objects using the
Prerequisites
The following prerequisites must be in place for this solution to be possible.
Oracle DBMS
An Oracle DBMS hosting the required Schema Objects needs to be available. In this document, the Oracle Human Resources sample database will be used to demonstrate the process.
ODBC Driver for Oracle
An Oracle ODBC Driver is required for Linking the Oracle Schema Objects into the Virtuoso Server.
The ora10ma
will be assumed to exist on the machine hosting the Virtuoso Server.
Virtuoso Universal 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 SP1
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.
Tasks
Ensure Oracle Primary Keys (PKs) are not nullable
The Visual Studio 2008 Entity Data Model (EDM) requires that all primary keys are NOT Nullable and will fail to generate an EDM if any are. Thus, ensure any tables to be used are defined as not nullable in the Oracle database schema before attempting to generate an EDM. In the case of the Oracle Human Resources database, no primary keys are nullable. Therefore, this should not be an issue in this case.
Install and configure OpenLink ODBC Driver for Oracle
The Virtuoso Virtual Database engine uses ODBC as the connectivity mechanism for linking remote database objects into its local schema.
Thus, an Oracle ODBC Driver must be available with a suitably configured DSN for connecting to the target database.
The
Installation instructions for the
Install and configure OpenLink Virtuoso Universal Server
Linking Oracle tables into Virtuoso
Creating Visual Studio hosted Entity Data Model (EDM)
Using EDM to create Entity Framework based applications
Now that a Microsoft Entity Data Model has been created for the Oracle Human Resources database, Entity Framework applications can be created to make use of it.
Entity Frameworks based ADO.NET Data Service
Visual Studio Windows Form Application
Referenced by...