The FROM Clause

The FROM clause is represented by the abstract class, fromExp. Currently NonJoinExp is the only direct subclass of fromExp. The NonJoinExp represents FROM clauses with only one table (CIM class) to which the select operation should be applied.

The FROM clause identifies the class in which to search for instances that match the query string. In SQL terms, the FROM clause identifies a qualified attribute expression, which is the name of a class to search. A qualified attribute expression identifies the table and class. We currently support only non-join expressions, which means that a valid WQL FROM clause includes only a single class.