针对目前所使用的增强型ER模型，本文介绍了对该模型中的超类/子类，特化和概化，以及超类型/子类型联系中的约束的无损语义转换方法。实践证明该转换方法具有很好的实用性，能对后续的算法设计起到很好的作用% Aiming at the existing enhanced ER mode,this paper provides a new transforming method without losing any semantics between superclass and subclass,and the introduction of superclass,subclass,specialization, generalization of the mode is given. This method is effective in practice,which plays a very good effect on subsequent algorithm.
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