How do we model transactions which have Header and Detail records (i.e Order and Order Line) using a Data Vault modeling approach

Seperate Hubs are created for the Order Header and the Order Lines.

Details about the Order (Order Date, Total Order Amount) are stored in the Order Satellite, details about the Order Line are stored in the Order Line Satellite (Product, Product Unit Price, Product Quantity, Total Order Line Amount).

A Link is created to define the relationship for the Customer who placed the Order.  A second Link is created to define the relationship for the Order, Order Lines and the Product for each Order Line.

The Order Hub drives the unit of work / grain for the Customer | Order link.  The Order Line Hub drives the unit of work / grain for the Order | Order Line | Product link 

A variation on this pattern is where we extend the detail driven link (Order Line) to include the Hubs from the Header driven link (Order)

So in this example we add Customer so the link becomes Customer | Order | Order Line | Product link.  This removes the need to combine the two links if you need to report on which Customer ordered the products.

TBD

Examples of Header/Detail source tables you might find are:

• • Order / Order Line
  • Order / Line Item
  • Invoice / Invoice Line
  • Product / Product Variant

AGAINST