How to Access Certinia 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 Certinia 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 Certinia Entity Framework 6 assembly and the connection string.

   There are several authentication methods available for connecting to Certinia: login credentials, SSO, and OAuth.

   Authenticating with a Login and Token

   Set the User and Password to your login credentials. Additionally, set the SecurityToken. By default, the SecurityToken is required, but you can make it optional by allowing a range of trusted IP addresses.

   To disable the security token:

   1. Log in to Certinia and enter "Network Access" in the Quick Find box in the setup section.
   2. Add your IP address to the list of trusted IP addresses.

   To obtain the security token:

   1. Open the personal information page on certinia.com.
   2. Click the link to reset your security token. The token will be emailed to you.
   3. Specify the security token in the SecurityToken connection property or append it to the Password.

   Authenticating with OAuth

   If you do not have access to the user name and password or do not want to require them, use the OAuth user consent flow. See the OAuth section in the Help for an authentication guide.

   Connecting to Certinia Sandbox Accounts

   Set UseSandbox to true (false by default) to use a Certinia sandbox account. Ensure that you specify a sandbox user name in User.

   <configuration>
    ... 
    <connectionStrings>
    <add name="CertiniaContext" connectionString="Offline=False;User=myUser;Password=myPassword;Security Token=myToken;InitiateOAuth=GETANDREFRESH;" providerName="System.Data.CData.Certinia" />
    </connectionStrings>
    <entityFramework>
    <providers>
    ... 
    <provider invariantName="System.Data.CData.Certinia" type="System.Data.CData.Certinia.CertiniaProviderServices, System.Data.CData.Certinia.Entities.EF6" />
    </providers>
    <entityFramework>
   </configuration>
   </code> 
   

4. Add a reference to System.Data.CData.Certinia.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 CertiniaContext. 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 CertiniaContext : DbContext {
    public CertiniaContext() { }
   
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
    // To remove the requests to the Migration History table
    Database.SetInitializer<CertiniaContext>(null); 
    // To remove the plural names 
    modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    } 
   }
   

7. Create another .cs file and name it after the Certinia entity you are retrieving, for example, Account. 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("Account")]
   public class Account {
    [System.ComponentModel.DataAnnotations.Key] 
    public System.String BillingState { get; set; }
    public System.String Name { get; set; }
   }
    
   

8. Now that you have created an entity, add the entity to your context class:

   public DbSet<Account> Account { set; get; }
   

9. With the context and entity finished, you are now ready to query the data in a separate class. For example:

   CertiniaContext context = new CertiniaContext();
   context.Configuration.UseDatabaseNullSemantics = true;
   var query = from line in context.Account select line;