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

   The driver connects to JD Edwards through your Application Interface Services (AIS) Server. Set the following connection properties:

   • URL: The base HTTPS URL of your AIS Server (e.g., https://jde-ais.example.com:8300).
   • User: Your JD Edwards username.
   • Password: Your JD Edwards password.
   • Environment (optional): The JD Edwards environment to use (e.g., PD920 for production or DV920 for development). If not specified, the AIS Server's default environment is used.
   • Role (optional): The JD Edwards role for the session. If not specified, the AIS Server's default role is used.
   • DeviceName (optional): An identifier for the connecting device or application, used for auditing and logging on the AIS Server.
   • Jasserver (optional): The specific Java Application Server (JAS) instance to route requests through, useful in clustered environments.

   Choosing Which Data Is Exposed

   JD Edwards organizes tables and business views by System Code, and the driver exposes each System Code as its own schema. Use these properties to control which schemas are available:

   • DataModel: One or more ERP modules (comma-separated) whose System Codes are exposed as schemas, or All to expose every System Code in the connected instance. Defaults to FinancialManagement.
   • SystemCodes: A comma-separated list of additional System Codes to expose alongside those from DataModel (e.g., 42,43).

   When you connect, the driver sends your credentials to the AIS Server to obtain a session token and caches it. The driver requests a new token automatically before the session expires.

   
   
   <configuration>
      ... 
     <connectionStrings>
       <add name="JDEdwardsContext" connectionString="Offline=False;URL=https://your-jde-environment-app.example.com;User=admin;Password=myPassword;" providerName="System.Data.CData.JDEdwards" />
     </connectionStrings>
     <entityFramework>
       <providers>
          ... 
         <provider invariantName="System.Data.CData.JDEdwards" type="System.Data.CData.JDEdwards.JDEdwardsProviderServices, System.Data.CData.JDEdwards.Entities.EF6" />
       </providers>
     <entityFramework>
   </configuration>
   </code> 
   

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

7. Create another .cs file and name it after the JD Edwards entity you are retrieving, for example, AccountsPayable.AccountLedger. 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("AccountsPayable.AccountLedger")]
   public class AccountsPayable.AccountLedger {
     [System.ComponentModel.DataAnnotations.Key] 
     public System.String DocumentNumber { get; set; }
     public System.String Amount { get; set; }
   }
       
   

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

   
   
   public DbSet<AccountsPayable.AccountLedger> AccountsPayable.AccountLedger { set; get; }
   

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

   
   JDEdwardsContext context = new JDEdwardsContext();
   context.Configuration.UseDatabaseNullSemantics = true;
   var query = from line in context.AccountsPayable.AccountLedger select line;