[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f-y8qS3QIbxJJPHaOVYIHFfLhflrXydNHlMtdjsasbjM":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":15,"related":16,"source":26,"type":31},[],"2025-12-13 11:20:20",1074501421,[8,9,10,11],"关系模型数据库系统","网状模型数据库系统","层次模型数据库系统","面向对象模型数据库系统",{"courseImg":13,"courseName":14},"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F757d92badb28516db1ac0d11a5eb7a6e.jpg","数据库原理及开发应用","主流的模型数据库系统是( )",[17,28,32,40,45,54,59,64,73,78],{"answer":18,"createTime":5,"id":19,"options":20,"question":25,"source":26,"type":27},[],1074501416,[21,22,23,24],"my_name","name","123","#123","下列正确的标识符有( )","v2",1,{"answer":29,"createTime":5,"id":6,"options":30,"question":15,"source":26,"type":31},[],[8,9,10,11],0,{"answer":33,"createTime":5,"id":34,"options":35,"question":38,"source":26,"type":39},[],1074501527,[36,37],"对","错","SQL语言中,利用字符串函数操作," SELECT LEFT('2020年02月29日',4)"的结果是字符串"2020".( )",3,{"answer":41,"createTime":5,"id":42,"options":43,"question":44,"source":26,"type":39},[],1074501545,[36,37],"用户定义完整性是指要求表中的每一行具有唯一的标识.( )",{"answer":46,"createTime":5,"id":47,"options":48,"question":53,"source":26,"type":31},[],1074501549,[49,50,51,52],"SELECT * FROM Book WHERE Author LIKE '%有为%'","SELECT * FROM Library WHERE Author LIKE '有为'","SELECT * FROM Book WHERE Author LIKE '有为'","SELECT * FROM Library WHERE Author = '有为'","要查询Library数据库Book表中作者名中含有"有为"的书籍信息,可用( )命令",{"answer":55,"createTime":5,"id":56,"options":57,"question":58,"source":26,"type":39},[],1074501653,[36,37],"唯一索引中不允许插入重复的列值.( )",{"answer":60,"createTime":5,"id":61,"options":62,"question":63,"source":26,"type":39},[],1074501659,[36,37],"连接是关系型数据库中常用的多表查询数据的模式.( )",{"answer":65,"createTime":5,"id":66,"options":67,"question":72,"source":26,"type":31},[],1074501668,[68,69,70,71],"abc","abcd","abcde","aceg","语句"select substring('abcdefg',1,4)"返回的结果是( )",{"answer":74,"createTime":5,"id":75,"options":76,"question":77,"source":26,"type":39},[],1074501683,[36,37],"使用SQL Server Management Studio 删除数据库后,仍然可以恢复内容.( )",{"answer":79,"createTime":5,"id":80,"options":81,"question":86,"source":26,"type":31},[],1074501738,[82,83,84,85],"select sdept ,avg(sage) from student group by sdept having avg(sage) >20","select sdept ,avg(sage) from student where ssex='女' group by sdept","select sdept ,avg(sage) from student where ssex='女' group by sdept having avg(sage) >20","select sdept ,avg(sage) from student where ssex='女' and avg(sage) >20 group by sdept","针对表Student (sno,sname,ssex,sage,sdept),其中sno为学号,sname为姓名,ssex为性别,sage为年龄,sdept为系别.查询女生平均年龄超过20岁的系别以及女生平均年龄.( )"]