5. Simple Relationship Expression for TADB Normal Group Attributes

Purpose

Determine if an order item goes to a customer in NY.

Assumptions

  1. There are two Item types (in the expression), defined as follows.

Order

Invoice information includes what the customer wants.

Customer

Information includes address and billing.

  1. There is one Attribute group (in the expression), defined as follows.

Address

Attributes include State.

  1. When an Order item is created, it is associated with the Customer item that should receive the finished product.

Query Expression

TestItem(“Order1”,”Customer{Address.State=’NY’}”)

Where

Criteria

Is/are the:

TestItem

Sub-expression test.

Order1

Order item

State

Address group attribute

'NY'

State attribute value.

Expression says:

Find Customer items that have a relationship with the item Order1

Where the

Customer item’s Address (group) contains NY as the value for its State (attribute).

Note: The relationships are looked for in the TADB’s RelatedItems table.

.bnf syntax Expression

ItemType{Expression}

This syntax means that:

Relationships can be combined and nested to near limitless complexity

Parentheses can be combined and nested to near limitless complexity.

More information

Order Execution Mgt. Query expression descriptions.