Bug 195970 Two issues when evaluate a query inlcuding a subquery[07]
Description: Currently, when evaluating a query which includes a subquery, the query will be evaluated twice. The binding of query will pass to subquery twice. If user write a java script such as new Date() and i++. The result of query will be incorrect. Another issue: when write the report document, the binding of query will be written twice and the performance is not good to evalulate it twice.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedSubquery.java
protected DataSourceRuntime findDataSource( )
		{
			
			return null;
		}
		
		/*
		 * @see org.eclipse.birt.data.engine.impl.PreparedQuery.Executor#newDataSetRuntime()
		 */
		protected DataSetRuntime newDataSetRuntime()
		{
			return new SubqueryDataSetRuntime( this );
		}
		
		/*
		 * @see org.eclipse.birt.data.engine.impl.PreparedQuery.Executor#createOdiQuery()
		 */
		protected IQuery createOdiQuery( ) throws DataException
		{
			
			return DataSourceFactory.getFactory( )
					.getEmptyDataSource( session )
					.newCandidateQuery( );
		}
		
		/*
		 * @see org.eclipse.birt.data.engine.impl.PreparedQuery.Executor#executeOdiQuery()
		 */
		protected IResultIterator executeOdiQuery( IEventHandler eventHandler ) 
				throws DataException