[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fR_GdQSFTuMBUWcdUAL-TVJg4mwYQ484hZ_MxvfFAuw8":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":19,"related":20,"source":30,"type":31},[],"2024-11-08 16:45:52",165035626,[8,9,10,11],"alter table stu add constraint fk_sid foreign key(sid) references stu(sid)","alter table stu add constraint fk_sid foreign key(sid) references score(sid)","alter table score add constraint fk_sid foreign key(sid) references sore(sid)","alter table score add constraint fk_sid foreign key(sid) references stu(sid)",{"count":13,"courseId":14,"courseImg":15,"courseName":16,"workId":17,"workName":18},29,"cdfb95746863db6b34b27929a0dc84bb","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F10aeb6ec6a3a05cebf0d059321461a69.jpg","MySQL数据库","work_38715317","作业4:数据表管理","设置score表的sid列为外键,关联stu表的sid列,可以使用以下哪条命令实现",[21,32,41,50,59,68,77,86,95,98],{"answer":22,"createTime":5,"id":23,"options":24,"question":29,"source":30,"type":31},[],165035618,[25,26,27,28],"create table stu (sid int not null, sname varchar(20), nation varchar(20) default 汉族)","create table stu (sid int not null, sname varchar(20), nation varchar(20) default('汉族'))","create table stu (sid int not null, sname varchar(20), nation varchar(20) default(汉族))","create table stu (sid int not null, sname varchar(20), nation varchar(20) default '汉族')","设置stu表的nation字段默认值为汉族,则可以使用以下哪种方法","v1",0,{"answer":33,"createTime":5,"id":34,"options":35,"question":40,"source":30,"type":31},[],165035619,[36,37,38,39],"alter table score drop foreign key","alter table score drop fk_sid","alter table score drop foreign key fk_sid","alter table score drop constraint fk_sid","删除score表的外键约束fk_sid,其命令可以为以下哪一条",{"answer":42,"createTime":5,"id":43,"options":44,"question":49,"source":30,"type":31},[],165035620,[45,46,47,48],"主键约束","唯一索引","外键约束","唯一约束","引用完整性就是()",{"answer":51,"createTime":5,"id":52,"options":53,"question":58,"source":30,"type":31},[],165035621,[54,55,56,57],"create table score( sid int not null, cid int not null, grade float), primary key(sid), primary key(cid))","create table score( sid int not null, cid int not null, grade float, primary key(sid,cid))","create table score( sid int not null primary key, cid int not null, grade float), primary key(cid))","create table score( sid int not null primary key, cid int not null primary key, grade float))","score表的主键建立在sid和cid字段上(联合主键),以下创建score表正确的语句是",{"answer":60,"createTime":5,"id":61,"options":62,"question":67,"source":30,"type":31},[],165035622,[63,64,65,66],"alter table stu drop constraint sid","alter table stu drop primary key","alter table stu drop primary keys","alter table stu drop primary key sid","删除stu表,建立在sid列上的主键,可使用以下哪条命令",{"answer":69,"createTime":5,"id":70,"options":71,"question":76,"source":30,"type":31},[],165035623,[72,73,74,75],"在两表的关系中,主键用来在一个表中引用来自于另一个表中的特定记录","一个表的主键可以由多个关键字共同组成,且主键的列不能包含空值","主键可以不唯一","一般用主键定义表中所有行能唯一标识","下列选项中,说法有误的是( )",{"answer":78,"createTime":5,"id":79,"options":80,"question":85,"source":30,"type":31},[],165035624,[81,82,83,84],"外键用于建立和加强两个表数据之间的连接","外键是指引用数据库表中的一列或多列","外键是指引用另一个表中的一列或多列","外键引用的列应该具有主键约束或唯一约束","下面关于外键说法有误的是()",{"answer":87,"createTime":5,"id":88,"options":89,"question":94,"source":30,"type":31},[],165035625,[90,91,92,93],"create table stu (id int not null auto, sname varchar(20), nation varchar(20) default '汉族')","create table stu (id int not null auto_increment, sname varchar(20), nation varchar(20) default '汉族')","create table stu (id int not null auto_increments, sname varchar(20), nation varchar(20) default '汉族')","create table stu (id int not null increment, sname varchar(20), nation varchar(20) default '汉族')","如果在创建stu表的时候要求id列为自动增长字段(初始值为1,增量为1),则可使用以下哪种方法实现",{"answer":96,"createTime":5,"id":6,"options":97,"question":19,"source":30,"type":31},[],[8,9,10,11],{"answer":99,"createTime":5,"id":100,"options":101,"question":102,"source":30,"type":31},[],165035627,[47,46,45,48],"定义外关键字与主关键字之间的引用规则的是()"]