Bug 132805 Set descending to outer group will affect inner group.
Description: Set descending to outer group will affect inner group. Steps to reproduce: 1. New a sample datasource and dataset from orders. 2. Drag the dataset to Layout. 3. Add a group on ordernumber, interval 10, descending. 4. Add another group on orderdate, interval day 2, ascending. 5. Preview. Expected result: Data are grouped correctly. Actual result: Inner group didn't work unless you set outer group's sort to asc.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutorUtil.java
else
			interval = DataType.ANY_TYPE;
		return interval;
	}
	
	/**
	 * Common code to extract the name of a column from a JS expression which is
	 * in the form of "row.col". If expression is not in expected format,
	 * returns null
	 * 
	 * @param cx
	 * @param expr
	 * @return
	 */
	public static ColumnInfo getColInfoFromJSExpr( Context cx, String expr )
	{
		int colIndex = -1;
		String colName = null;
		CompiledExpression ce = ExpressionCompilerUtil.compile( expr, cx );
		if ( ce instanceof ColumnReferenceExpression )
		{
			ColumnReferenceExpression cre = ( (ColumnReferenceExpression) ce );
			colIndex = cre.getColumnindex( );
			colName = cre.getColumnName( );
		}
		return new ColumnInfo( colIndex, colName );
	}
	
}