Identity Constraint Definition
(
Schema Component
Definition Component
Secondary Component
)
Names
Identity Constraint Definition
Identity-constraint Definitions
Subject Indicators
http://www.techquila.com/psi/xmlschema/component/cIdentity-constraint_Definitions
Description
An identity-constraint definition is an
association between a name and one of several varieties
of identity-constraint related to uniqueness and
reference. All the varieties use XPath expressions to
pick out sets of information items relative to
particular target element information items which are
unique, or a key, or a ·valid· reference, within a
specified scope. An element information item is only
·valid· with respect to an element declaration with
identity-constraint definitions if those definitions are
all satisfied for all the descendants of that element
information item which they pick out.