This topic assumes you have already gone through

• Creating a Simple Business Object and
  
• Creating a Business Entity
  

Child entity objects are generally used to implement entities that are composed of multiple tables. A typical example would be an invoice and it's line items:

Another example would be a product entity that has a number of attached images stored in a related table.

There are two different classes that need to be implemented for this functionality. The first one represents the actual collection. The second represents each item within the collection.

Note: In this example I assume we are adding a related table with product images and descriptions to our products database.

• Implementing the Collection
  
• Implementing the Collection Item
  
• Making the Main Entity Aware of the Sub Items
  
• Making the Business Object Aware of the New Table
  
• Using Non-Guid Primary Keys
  
• Preserving Referential Integrity in Identity Key Scenarios