Bug 200755 [smoke]Fail to preview Crosstab after deploy BIRT in application servers.[0601][1102]
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/AbstractExpressionCompiler.java
}
			else if ( rowColumn.getType( ) == Token.STRING )
			{
				return new ColumnReferenceExpression(
						this.isDataSetMode ? STRING_ROW : STRING_DATASETROW,
						rowColumn.getString());
			}
		}
		
		
		
		return null;
	}
	/**
	 * Check the expression is an aggregate expression. If so, returns an
	 * instance of AggregateExpression, otherwise return null
	 * 
	 * @param context
	 * @param parent
	 * @param callNode
	 * @return
	 * @throws DataException
	 */
	protected abstract AggregateExpression compileAggregateExpr( Context context, Node parent,
			Node callNode ) throws DataException;
	/**
	 * Check the expression is a complex expression. If so, returns an instance
	 * of ComplexExpression, otherwise return null
	 * 
	 * @param context