Ready to get started?

Learn more about the CData ADO.NET Provider for SAP Netweaver Gateway or download a free trial:

Download Now

Access SAP Netweaver Gateway Data with Entity Framework 6

This article shows how to access SAP Netweaver Gateway data using an Entity Framework code-first approach. Entity Framework 6 is available in .NET 4.5 and above.

Entity Framework is an object-relational mapping framework that can be used to work with data as objects. While you can run the ADO.NET Entity Data Model wizard in Visual Studio to handle generating the Entity Model, this approach, the model-first approach, can put you at a disadvantage if there are changes in your data source or if you want more control over how the entities operate. In this article you will complete the code-first approach to accessing SAP Netweaver Gateway data using the CData ADO.NET Provider.

  1. Open Visual Studio and create a new Windows Form Application. This article uses a C# project with .NET 4.5.
  2. Run the command 'Install-Package EntityFramework' in the Package Manger Console in Visual Studio to install the latest release of Entity Framework.
  3. Modify the App.config file in the project to add a reference to the SAP Netweaver Gateway Entity Framework 6 assembly and the connection string.

    SAP Gateway allows both basic and OAuth 2.0 authentication. You can use basic authentication to connect to your own account, or you can use OAuth to enable other users to retrieve data from your service with their accounts. In addition to authenticating, set the following connection properties to access SAP Gateway tables.

    • Url: Set this to the URL of your environment, or to the full URL of the service. For example, the full URL might appear as: https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/. In this example, the environment URL would just be: https://sapes5.sapdevcenter.com.
    • Namespace: Set the appropriate Service Namespace. In the example above, IWBEP is the namespace. It is optional if the full URL to the service is specified.
    • Service: Set this to the service you want to retrieve data from. In the example above, the service is GWSAMPLE_BASIC. It is not required if the full URL is specified.

    Authenticate via Basic Authentication

    In basic authentication, you use your login credentials to connect. Set the following properties:

    • User: This is the username you use to log in to SAP Gateway.
    • Password: This is the password you use to log in to SAP Gateway.

    Authenticate via OAuth Authentication

    You can connect to SAP Gateway using the embedded OAuth connectivity (without setting any additional authentication connection properties). When you connect, the OAuth endpoint opens in your browser. Log in and grant permissions to complete the OAuth process. See the OAuth section in the online Help documentation for more information on other OAuth authentication flows.

    <configuration> ... <connectionStrings> <add name="SAPGatewayContext" connectionString="Offline=False;User=user;Password=password;URL=https://sapes5.sapdevcenter.com/sap/opu/odata/IWBEP/GWSAMPLE_BASIC/;InitiateOAuth=GETANDREFRESH" providerName="System.Data.CData.SAPGateway" /> </connectionStrings> <entityFramework> <providers> ... <provider invariantName="System.Data.CData.SAPGateway" type="System.Data.CData.SAPGateway.SAPGatewayProviderServices, System.Data.CData.SAPGateway.Entities.EF6" /> </providers> <entityFramework> </configuration> </code>
  4. Add a reference to System.Data.CData.SAPGateway.Entities.EF6.dll, located in the lib -> 4.0 subfolder in the installation directory.
  5. Build the project at this point to ensure everything is working correctly. Once that's done, you can start coding using Entity Framework.
  6. Add a new .cs file to the project and add a class to it. This will be your database context, and it will extend the DbContext class. In the example, this class is named SAPGatewayContext. The following code example overrides the OnModelCreating method to make the following changes:
    • Remove PluralizingTableNameConvention from the ModelBuilder Conventions.
    • Remove requests to the MigrationHistory table.
    using System.Data.Entity; using System.Data.Entity.Infrastructure; using System.Data.Entity.ModelConfiguration.Conventions; class SAPGatewayContext : DbContext { public SAPGatewayContext() { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { // To remove the requests to the Migration History table Database.SetInitializer<SAPGatewayContext>(null); // To remove the plural names modelBuilder.Conventions.Remove<PluralizingTableNameConvention>(); } }
  7. Create another .cs file and name it after the SAP Netweaver Gateway entity you are retrieving, for example, SalesOrderLineItems. In this file, define both the Entity and the Entity Configuration, which will resemble the example below: using System.Data.Entity.ModelConfiguration; using System.ComponentModel.DataAnnotations.Schema; [System.ComponentModel.DataAnnotations.Schema.Table("SalesOrderLineItems")] public class SalesOrderLineItems { [System.ComponentModel.DataAnnotations.Key] public System.String ProductID { get; set; } public System.String Quantity { get; set; } }
  8. Now that you have created an entity, add the entity to your context class: public DbSet<SalesOrderLineItems> SalesOrderLineItems { set; get; }
  9. With the context and entity finished, you are now ready to query the data in a separate class. For example: SAPGatewayContext context = new SAPGatewayContext(); context.Configuration.UseDatabaseNullSemantics = true; var query = from line in context.SalesOrderLineItems select line;