[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fuVGQoTRhUwbyQ5zDhpG2CQ_a7jgIDhX3OrnhsgdSEY0":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":19,"related":20,"source":30,"type":31},[],"2024-11-28 19:07:04",167930793,[8,9,10,11],"1NF","3NF","BCNF","4NF",{"count":13,"courseId":14,"courseImg":15,"courseName":16,"workId":17,"workName":18},30,"1197ab5dcae109e97ef84d12a4c314c7","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fb7459ab6ad2ca982995f6f9920bada33.jpg","数据库原理及应用","work_39345705","作业4 范式","关系模式R\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F5ccf232472dcccb73101580dbd4cbac3.png\">2NF,则R一定是()",[21,32,41,47,52,57,66,75,84,93],{"answer":22,"createTime":5,"id":23,"options":24,"question":29,"source":30,"type":31},[],167930784,[25,26,27,28],"函数","函数依赖","范式","关系","关系规范化的实质是针对()进行的","v1",0,{"answer":33,"createTime":5,"id":34,"options":35,"question":40,"source":30,"type":31},[],167930785,[36,37,38,39],"插入、删除和数据冗余","提高查询速度","减少数据操作的复杂性","保证数据的安全性和完整性","关系数据库规范化是为解决关系数据库中()问题而引入的",{"answer":42,"createTime":5,"id":43,"options":44,"question":46,"source":30,"type":31},[],167930786,[9,10,45,8],"2NF","若关系模式R中,消除了非主属性对码的部分依赖,则R至少属于()",{"answer":48,"createTime":5,"id":49,"options":50,"question":51,"source":30,"type":31},[],167930787,[9,10,45,8],"若关系模式R中,每一个函数依赖的决定因素都含码,则R至少属于()",{"answer":53,"createTime":5,"id":54,"options":55,"question":56,"source":30,"type":31},[],167930788,[9,10,45,8],"设R(A,B,C),F={A→B,B→C},则R最高属于()",{"answer":58,"createTime":5,"id":59,"options":60,"question":65,"source":30,"type":31},[],167930789,[61,62,63,64],"可能是1NF","必定是BCNF","必定是3NF","必定是1NF","关系模式中,满足2NF的模式,()",{"answer":67,"createTime":5,"id":68,"options":69,"question":74,"source":30,"type":31},[],167930790,[70,71,72,73],"在R的某一关系中,若两个元组的X值相等,则Y值也相等","在R的每一关系中,若两个元组的X值相等,则Y值也相等","在R的某一关系中,X值应与Y值相等","在R的每一关系中,X值应与Y值相等","在关系模型R中,函数依赖X→Y的语义是()",{"answer":76,"createTime":5,"id":77,"options":78,"question":83,"source":30,"type":31},[],167930791,[79,80,81,82],"性别","学号","学号,姓名","学号,姓名,性别","设学生关系模式为:学生(学号,姓名,年龄,性别,成绩,专业),则该关系模式的主键是()",{"answer":85,"createTime":5,"id":86,"options":87,"question":92,"source":30,"type":31},[],167930792,[88,89,90,91],"自反律","传递律","伪传递律","增广律","如果X→Y(Y不包含于X,且Y不能决定X)和Y→Z成立,那么X→Z成立.这条规则称为()",{"answer":94,"createTime":5,"id":6,"options":95,"question":19,"source":30,"type":31},[],[8,9,10,11]]