• 2022-06-16
    假定有学生关系S,结构为S(SID, SNAME, AGE),其中SID为学号,SNAME为姓名,AGE为年龄。查询所有比“李军”年龄大的学生的姓名、年龄,正确的SQL语句是( )。
    A: SELECT SNAME, AGE FROM S WHERE AGE > ( SELECT AGE FROM S WHERE SNAME = '李军' )
    B: SELECT SNAME, AGE FROM S WHERE AGE >( SNAME= '李军' )
    C: SELECT SNAME, AGE FROM S WHERE AGE > ( SELECT AGE WHERE SNAME='李军' )
    D: SELECT SNAME, AGE FROM S WHERE AGE>李军.AGE
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    • 0

      对于学生信息表:student(sno,sname,sex,age,grade),查询学习成绩为空的学生的学号和姓名,下面语句正确的是 A: SELECT sno,sname FROM student WHERE grade=NULL B: SELECT sno,sname FROM student WHERE grade IS NULL C: SELECT sno,age FROM student WHERE grade IS NULL D: SELECT sno,age FROM student WHERE grade=NULL

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      检索所有比“李乐”年龄大的学生姓名、年龄和性别。正确的SELECT语句是( A )。 A: SELECT SN,AGE,SEX FROM SWHERE AGE>(SELECT AGE FROM S WHERE SN="李乐") B: SELECT SN,AGE,SEXFROM SWHERE SN="李乐" C: SELECT SN,AGE,SEX FROM SWHERE AGE>(SELECT AGEWHERE SN="李乐") D: SELECT SN,AGE,SEX FROM SWHERE AGE>李乐.AGE

    • 2

      基于“学生-选课-课程”数据库中如下三个关系: S(S#,SNAME,SEX,AGE),SC(S#,C#,GRADE),C(C#,CNAME,TEACHER) 若要求查找姓名中第一个字为“李”的学生号和姓名。下面列出的SQL语句中,哪个(些)是正确的 Ⅰ.SELECT S#,SNAME FROM S WHERE SNAME=’李%’ Ⅱ.SELECT S#,SNAME FROM S WHERE SNAME LIKE’李%’ Ⅲ.SELECT S#,SNAME FROM S WHERE SNAME LIKE’李_’ A: Ⅰ B: Ⅱ C: Ⅲ D: 全部

    • 3

      假设有三个基本表:学生表S、课程表C、学生选课表SC,它们的结构如下: S(S#,SN,SEX,AGE,DEPT) C(C#,CN) SC(S#,C#,GRADE)检索所有比“王华”年龄大的学生姓名、年龄和性别。正确的SQL语句是( )。 A: SELECT SN,AGE,SEX FROM S WHERE AGE>(SELECT AGE FROM S WHERE SN=”王华”) B: SELECT SN,AGE,SEX FROM S WHERE SN=”王华” C: SELECT SN,AGE,SEX FROM S WHERE AGE>(SELECT AGE WHERE SN=”王华”) D: SELECT SN,AGE,SEX FROM S WHERE AGE>王华.AGE

    • 4

      有学生表S,课程表C,成绩表SC,关系模式如下: Sno,Sn,Sex,Age,Dept)分别为学号、姓名,性别,年龄和系别。 Cno,Cn)分别为课程号和课程名。 (Sno,Cno,Grade)分别为学号,课程号和成绩。 所有比‘王强’年龄大的学生姓名、年龄和性别。正确的SQL语句是 A: SELECT Sn,Age,Sex FROMS WHERE Age >(SELECT Age FROM S WHERE Sn=’王强’) B: SELECT Sn,Age,Sex FROM S WHERE Sn=’王强’ C: SELECT Sn,Age,Sex FROM S WHERE Age > (SELECT Age WHERE Sn=’王强’) D: SELECT Sn,Age,Sex FROM S WHERE Age >王强.Age