Bug 124193 Parent axis doesn't work for recursive XPath
When table mapping for XML files is specified via recursive XPath: e.g. "//book", the parent axis access is broken for column mappings on such table: e.g. "../bookstore/@name" will not work. Same parent axis access works fine if non-recursive XPath is used for table mapping: e.g. "/bookstore/book".
data/org.eclipse.birt.report.data.oda.xml/src/org/eclipse/birt/report/data/oda/xml/util/RelationInformation.java
* 
	 * @param tableName
	 * @param columnName
	 * @return
	 */
	public String getTableOriginalColumnPath( String tableName, String columnName )
	{
		return ( (TableInfo) this.tableInfos.get( tableName ) ).getOriginalPath( columnName );
	}
	
	/**
	 * Return the path of a column in certain table.
	 * 
	 * @param tableName
	 * @param columnName
	 * @return
	 */
	public int getTableNestedColumnBackRefNumber( String tableName, String columnName )
	{
		return ( (TableInfo) this.tableInfos.get( tableName ) ).getBackRefNumber( columnName );
	}
	
	/**
	 * Return the type of a column in certain table.
	 * 
	 * @param tableName
	 * @param columnName
	 * @return
	 */
	public String getTableColumnType( String tableName, String columnName )