Without a solid background on object oriented design, we can quickly get lost in a world of objects, relations and classes.
如果没有坚实的面向对象设计基础，我们很快就会迷失在对象、关系和类的世界里。
2
More powerful representations, such as entity/relations or object models, are needed if one wants to perform a complex mapping of databases to each other or to query across heterogeneous databases.
更为有效的表达方法，例如实体关系或者对象模型，可以用来解决复杂的数据映射或者查询异构数据。
3
Our object is to further strengthen friendly relations between the two countries.