学生选课 ........\学生选课.doc ........\概念模型 ........\........\Conceptual Data Model 1.cdb ........\........\Conceptual Data Model 1.cdm ........\........\Conceptual Data Model 3.pdb ........\........\Conceptual Data Model 3.pdm ........\物理模型 ........\........\PhysicalDataModel_1.pdm ........\........\PhysicalDataModel_4.pdm ........\........\数据库文件 ........\........\..........\crebas.dat