This system used E-R chart method to design in order to minimum data redundancy and optimize data consistency and reduce updating abnormity.

本系统采用E -R图法进行规范化设计使得数据冗余最小，数据一致性好，更新异常问题不易发生。

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This system used E-R chart method to design in order to minimum data redundancy and optimize data consistency and reduce updating abnormity.

本系统采用E -R图法进行规范化设计使得数据冗余最小，数据一致性好，更新异常问题不易发生。

youdao