数据库中objects,classes,associations,generalizations,aggregations是什么意思

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数据库中objects,classes,associations,generalizations,aggregations是什么意思数据库中objects,classes,associations,g

数据库中objects,classes,associations,generalizations,aggregations是什么意思
数据库中objects,classes,associations,generalizations,aggregations是什么意思

数据库中objects,classes,associations,generalizations,aggregations是什么意思
objects:对象 classes:类 associations,:关联(表示一种关系)
generalizations:概括 aggregations:聚合(是一种函数)

objects, classes, associations, generalizations,aggregations
对象,类,关联,概括,聚合