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
* @see org.eclipse.birt.data.engine.impl.IPreparedQueryService#getDataSourceQuery()
	 */
	public PreparedDataSourceQuery getDataSourceQuery( )
	{
		
		return queryService.getDataSourceQuery( );
	}
	
	/*
	 * @see org.eclipse.birt.data.engine.impl.IPreparedQueryService#execSubquery(org.eclipse.birt.data.engine.odi.IResultIterator,
	 *      java.lang.String, org.mozilla.javascript.Scriptable)
	 */
	public IQueryResults execSubquery( IResultIterator iterator, String subQueryName, Scriptable subScope ) throws DataException
	{
		return this.preparedQuery.execSubquery( iterator, subQueryName, subScope );
	}
	
	/**
	 * @return group level of current sub query
	 */
	int getGroupLevel( )
	{
		return this.groupLevel;
	}
	
	/**
	 * Executes this subquery
	 * 
	 * @param parentIterator
	 * @param scope