说明：  erwin是一个数据库关系实体模型（ER Model）设计工具，与Power Designer（Sybase公司开发）成为最常用的两种数据库设计工具。目前该工具被CA收购，成为CA数据库解决方案中的一个关键部分。与微软的Vision相比，erwin只能设计er model，而且设计界面选项较多，相对来说并不那么友好，增加了使用的难度
(erwin is a database entity relationship model [ER Model] design tools, and Power Designer [Sybase developed] become the two most commonly used database design tool. CA is currently the tool was acquired and became CA database solution, a key part. Vision compared with Microsoft' s, erwin only design er model, and the design of interface options more, relatively speaking, not so friendly, and has increased the use of the difficulty of)