[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fnOGGobSNVnawd2xhcyhBY-wZOcxjLCnIs3r8BVONAk8":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",167930792,[8,9,10,11],"自反律","传递律","伪传递律","增广律",{"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","如果X&rarr;Y(Y不包含于X,且Y不能决定X)和Y&rarr;Z成立,那么X&rarr;Z成立.这条规则称为()",[21,32,41,50,55,60,69,78,87,90],{"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":49,"source":30,"type":31},[],167930786,[45,46,47,48],"3NF","BCNF","2NF","1NF","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":51,"createTime":5,"id":52,"options":53,"question":54,"source":30,"type":31},[],167930787,[45,46,47,48],"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":56,"createTime":5,"id":57,"options":58,"question":59,"source":30,"type":31},[],167930788,[45,46,47,48],"设R(A,B,C),F={A&rarr;B,B&rarr;C},则R最高属于()",{"answer":61,"createTime":5,"id":62,"options":63,"question":68,"source":30,"type":31},[],167930789,[64,65,66,67],"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":70,"createTime":5,"id":71,"options":72,"question":77,"source":30,"type":31},[],167930790,[73,74,75,76],"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&rarr;Y的语义是()",{"answer":79,"createTime":5,"id":80,"options":81,"question":86,"source":30,"type":31},[],167930791,[82,83,84,85],"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":88,"createTime":5,"id":6,"options":89,"question":19,"source":30,"type":31},[],[8,9,10,11],{"answer":91,"createTime":5,"id":92,"options":93,"question":95,"source":30,"type":31},[],167930793,[48,45,46,94],"4NF","关系模式R\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F5ccf232472dcccb73101580dbd4cbac3.png\">2NF,则R一定是()"]