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    WebDAV System Administrator 2017-06-13 05:40:14

    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 OpenLink Virtuoso Universal Server. This is achieved by linking the required Oracle Schema objects into Virtuoso using its built in Virtual Database engine and then using the Virtuoso ADO.NET Entity Framework provider to query the remote Oracle Schema objects linked into the Virtuoso Server.

    Prerequisites

    The following must be in place to complete this exercise.

    1. Microsoft Visual Studio 2008 SP1 (or later)
      Microsoft Visual Studio 2008 Service Pack 1 (or later) is required, as previous versions do not include the necessary Entity Framework support.

    2. Virtuoso ADO.NET Entity Framework Provider, v5.10 or later
      The ADO.NET Entity Framework Provider must be installed on the Visual Studio development and deployment host(s). Version 5.10.x or later is required, as previous versions do not include the necessary Entity Frameworks support.

    3. Virtuoso Universal Server, v5.10 or later
      Virtuoso Universal Server Release 5.10 or later is required, as previous versions do not include the necessary Entity Frameworks support. This may be on any host which is TCP/IP accessible from the Visual Studio development and deployment host(s).

    4. ODBC Driver for Oracle
      The Virtuoso Server uses an ODBC Driver for Oracle to link in the Oracle Schema Objects. The OpenLink Multi-Tier ODBC Driver for Oracle will be used in this document, and a functional ODBC Data Source Name (DSN) of "ora10ma-hr" will be assumed to exist on the machine hosting the Virtuoso Server. Any ODBC compliant driver for Oracle should work.

    5. Oracle DBMS
      An Oracle DBMS hosting the required Schema Objects needs to be available. This may be on any host which is TCP/IP accessible from the Virtuoso Server host. In this document, the Oracle Human Resources database will be used to demonstrate the process.

    Tasks

    1. Ensure Oracle Primary Keys (PKs) are not nullable
      The Visual Studio 2008 Entity Data Model (EDM) requires that all primary keys are NOT Nullable. Visual Studio 2008 will fail to generate an EDM if any are. Therefore, ensure any primary keys 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, all primary keys are non nullable. Thus, this should not be an issue in this case.

    2. Install and configure the OpenLink ODBC Driver for Oracle

    3. Install and configure OpenLink Virtuoso Universal Server

    4. Link Oracle tables and other schema objects into OpenLink Virtuoso

    5. Create a Visual Studio-hosted Entity Data Model (EDM)

    6. Use the EDM to create an Entity Frameworks-based ADO.NET Data Service

    7. Use the EDM to create an Entity Frameworks-based Windows DataGrid Form Application

    CategoryDocumentation CategoryVirtuoso CategoryEntityFrameworks CategoryDotNET CategoryOracle