Appendix B. Command Language

JBoss Data Virtualization sends commands to your Translator in object form. These classes are all defined in the org.teiid.language package. These objects can be combined to represent any command sent to the Translator. However, it is possible to specify that your Translator can only accept certain kinds of constructs via the capabilities defined on the ExecutionFactory class. Refer to the section on translator capabilities for more information.

The language objects all extend from the LanguageObject interface. Language objects should be thought of as a tree where each node is a language object that has zero or more child language objects of types that are dependent on the current node.

All commands sent to your Translator are in the form of these language trees, where the root of the tree is a subclass of Command. Command has several sub-interfaces, namely:

Important components of these commands are expressions, criteria, and joins, which are examined in closer detail below. For more on the classes and interfaces described here, refer to the JBoss Data Virtualization Javadoc.