Type casting refines the results of a query. A type is
not assigned to schema elements that can have more than one valid
type. You define the types for these elements with the cast
to type feature in the schema view bar.
About this task
Type casting works as an alternate filter for data source
elements. A cast query filters the results of the regular query to
return only the elements that can be cast to the selected type. After
the type is selected, it becomes available in the
Data
Source Schema view under the
anyType element.
Queries built using cast allow access to all the child elements and
attributes of the type cast. The result set returned by a cast query
is identical to the result set returned by a query that is filtered
with an equivalent
IsKindOf predicate. The difference
between the cast query and filtered query is that a cast query gives
access to the cast type attributes and child elements while the filtered
query does not.
Note: IBM® Rational® Tau and IBM Rational Rhapsody® data
sources support type casting.