How to Access HCL Domino Data Using Entity Framework

Microsoft Entity Framework serves as an object-relational mapping framework for working with data represented as objects. Although Visual Studio offers the ADO.NET Entity Data Model wizard to automatically generate the Entity Model, this model-first approach may present challenges when your data source undergoes changes or when you require greater control over entity operations. In this article, we will delve into the code-first approach for accessing HCL Domino data through the CData ADO.NET Provider, providing you with more flexibility and control.

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 HCL Domino Entity Framework 6 assembly and the connection string.

   Prerequisites

   The connector requires the Proton component to be installed. Normally, Proton is distributed as part of the AppDev pack. See the HCL documentation for instructions on acquiring and installing Proton or the AppDev pack.

   Once the Proton service is installed and running, you will also need to create a user account and download its Internet certificate. This certificate can be used to set the connector certificate connection properties.

   Authenticating to Domino

   • Server: The name or IP address of the server running Domino with the Proton service.
   • Port: The port number that the Proton service is listening on.
   • Database: The name of the database file, including the .nsf extension.
   • SSLClientCertType: This must match the format of the certificate file. Typically this will be either PEMKEY_FILE for .pem certificates or PFXFILE for .pfx certificates.
   • SSLClientCert: The path to the certificate file.
   • SSLServerCert: This can be set to (*) if you trust the server. This is usually the case, but if you want to perform SSL validation, you may provide a certificate or thumbprint instead. See the documentation for SSLServerCert for details.

   Additional Server Configuration

   The connector supports querying Domino views if any are defined. Before views can be queried by the connector they must be registered with the design catalog.

   Please refer to the Catalog Administration section of the AppDev pack documentation for details on how to do this.

   <configuration> ... <connectionStrings> <add name="DominoContext" connectionString="Offline=False;Server=https://domino.corp.com;Database=names.nsf;Port=3002;SSLClientCertType=PEMKEY_FILE;SSLClientCert=full_path_of_certificate.pem;SSLServerCert=*" providerName="System.Data.CData.Domino" /> </connectionStrings> <entityFramework> <providers> ... <provider invariantName="System.Data.CData.Domino" type="System.Data.CData.Domino.DominoProviderServices, System.Data.CData.Domino.Entities.EF6" /> </providers> <entityFramework> </configuration> </code>
4. Add a reference to System.Data.CData.Domino.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 DominoContext. 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 DominoContext : DbContext { public DominoContext() { } protected override void OnModelCreating(DbModelBuilder modelBuilder) { // To remove the requests to the Migration History table Database.SetInitializer<DominoContext>(null); // To remove the plural names modelBuilder.Conventions.Remove<PluralizingTableNameConvention>(); } }
7. Create another .cs file and name it after the HCL Domino entity you are retrieving, for example, ByName. 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("ByName")] public class ByName { [System.ComponentModel.DataAnnotations.Key] public System.String Name { get; set; } public System.String Address { get; set; } }
8. Now that you have created an entity, add the entity to your context class: public DbSet<ByName> ByName { set; get; }
9. With the context and entity finished, you are now ready to query the data in a separate class. For example: DominoContext context = new DominoContext(); context.Configuration.UseDatabaseNullSemantics = true; var query = from line in context.ByName select line;