外部属性数据库 meaning in English

external attribute database

On the base of the grading model , the article discusses the important effects of farmland grading course , and the whole grading processing . thirdly , the author implements a farmland grading information system . the system selects the new grading model as farmland grading method , component geographic information system ( gis ) as developing means
系统实现了地图集管理、地图操作、地图编辑、属性数据管理、外部属性数据库的连接、定级因素的维护、定级因素权重维护、定级指标体系、因素数据表的创建、定级处理、专题图的制作和系统管理等功能。