Query/View/Transformation Operational Mapping Language - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 597

The models used in the transformation are installed as part of the QVTO
examples feature. To see the structure of the models, you can use the Metamodel
Explorer ( Window Metamodel

Explorer ), or you can obtain the Ecore models themselves from the Eclipse CVS
repository and render a diagram. Alternatively, placing the cursor on the
modeltype declaration at the top of the Simpleuml_to_Rdb.qvto file and
pressing F3 opens the Metamodel Explorer and selects the model in the tree.
The M2M QVTO example Simple UML model is slightly more complicated
than the one in the specification, but it remains simpler than the actual UML
metamodel.
The rdb.ecore model provided in the sample is much more complex than
the model used in the specification. The example model includes additional
datatypes, views, and constraints subpackages.
The sample project also includes an instance of the Simple UML model to
allow for invocation of the script. To run, expand the Run button on the main
toolbar and select the SimpleUML to RDB launch configuration. A Simpleuml_
to_Rdb.rdb model appears in the root of the sample project. You can open this
and the source pim.simpleuml model to compare input and output results in
the context of the discussion to follow.
The mapping between these two models is straightforward. Although the
OML has no graphical notation, the notation used to describe the Relational
implementation can be helpful in understanding the mapping. In fact, you could
use GMF to implement a similar notation and diagram for QVTO. This exercise
is left to you, with the suggestion that you consider contributing the solution to
the M2M project.
Let's begin with the transformation declaration. Both the Simple UML and
RDBMS models are declared using modeltype statements at the top of the file,
along with the transformation declaration itself. Note that there is no strict
qualifier in the modeltype statements, leaving you free to modify the model and
reuse this script—that is, as long as you don't change it so that it breaks the
script. Also, no where clauses restrict our input model from being passed to the
transformation.

→ Show View → Other → Operational QVT →

modeltype UML uses
'http://www.eclipse.org/qvt/1.0.0/Operational/examples/simpleuml';
modeltype RDB uses
'http://www.eclipse.org/qvt/1.0.0/Operational/examples/rdb';
transformation Simpleuml_To_Rdb( in uml : UML, out RDB);

Notice that the sample uses a shorter notation for the uses clause, compared
to the version in the specification, opting to not surround the URI with the model