ADO.NET Entity : getting data from 3 tables

Question

I have following table structure:

Table: Plant
 PlantID: Primary Key
 PlantName: String

Table: Party
 PartyID: Primary Key
 PartyName: String
 PlantID: link to Plant table

Table: Customer
 PartyID: Primary Key, link to Party
 CustomerCode: String 

I'd like to have Customer entity object with following fields:

 PartyID: Primary Key
 CustomerCode: String
 PartyName: String
 PlantName: String

I am having trouble with PlantName field (which is brought from Plant table I connected Customer to Party and Party to Plant with associations However I can not connect Customer to Plant with association ( because it does not have one) I can not add Plant table to mapping, when I do that - I am getting following error:

Error 3024: Problem in Mapping Fragment starting at line 352: Must specify mapping for all key properties (CustomerSet.PartyID) of the EntitySet CustomerSet

Removing Plant association works. Any hints or directions very appreciated.

Answer 1

You can get these fields by using the reference path on the Entity Object.

To get the PartyName, use this syntax: Customer.Party.PartyName

To get the PlantName, use this syntax: Customer.Party.Plant.PlantName

Answer 2

You can extend the Customer entity by using the public partial class:

public partial class Customer
{
  public string PartyName
  {
    get { return Party.PartyName; }
    set { Party.PartyName = value; }
  }

  public string PlantName
  {
    get { return Party.Plant.PlantName; }
    set { Party.Plant.PlantName = value; }
  }
}