Bug 131011 Support running query based on report document data
Data Engine should support running a query based on data set and expression data stored in a report document. This bugzilla entry serves as a repository for design docs and notes related to this feature.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/api/querydefn/BaseTransform.java
* Add one filter to the filter list
	 */
	public void addFilter( IFilterDefinition filter) 
	{
		filters.add(filter);
	}
	
	/**
	 * Returns an unordered collection of subqueries that are alternative views of
	 * the result set for this transform. Objects are of type <code>SubqueryDefinition</code>.
	 * 
	 * @return the subqueries for this transform
	 */
	
	public Collection getSubqueries( )
	{
		return subqueries;
	}
	/**
	 * Add a subquery to the list
	 * @param subquery one subquery to add to the subquery set
	 */
	public void addSubquery( SubqueryDefinition subquery) 
	{
	    subqueries.add(subquery);
	}
	
	/**
	 * Returns the sort criteria as an ordered list of <code>SortDefinition</code> objects.
	 *