• 2022-05-29
    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
  • B

    举一反三

    内容

    • 0

      若要求查找姓名中第一个字为‘刘’的学生号和姓名。下面列出的SQL语句中,( )是正确的。 A: SELECT S#,SNAME,FROM S WHERE SNAME=‘刘%’ B: SELECT S#,SNAME,FROM S WHERE SNAME=‘刘-’ C: SELECT S#,SNAME,FROM S WHERE SNAME LIKE‘刘%’ D: SELECT S#,SNAME,FROM S WHERE SNAME LIKE ‘刘-’

    • 1

      若要求查找姓名中第一个字为“刘”的学生号和姓名。下面列出的SQL语句中, ( )是正确的。 A: SELECT S#,SNAME FROM,S WHERE SNAME='刘%' B: SELECT S#,SNAME FROM S WHERE SNAME='刘_' C: SELECT S#,SNAME FROM S WHERES NAME LIKE'刘%' D: SELECT S#,SNAME FROM S WHERES NAME LIKE'刘'

    • 2

      若要求查找“年龄大于18岁学生的学生号和姓名”,正确的SQL语句是( )。 A: SELECT S#,SNAME FROM S WHERE AGE>18 B: SELECT S#,SNAME FROM S WHERE AGE>=18 C: SELECT S#,SNAME FROM S WHERE AGE>’18’ D: SELECT S#,SNAME FROM S WHERE AGE>=’18’

    • 3

      有关系S(S#,SNAME,SAGE),C(C#,CNAME),SC(S#,C#,GRADE)。若要查找分数(grade)不及格的学生姓名(sname),则以上正确的有?( ) A: SELECT sname FROM s, sc WHERE grade<60 B: SELECT sname FROM s WHERE sno IN(SELECT Cno FROM sc WHERE grade<60) C: SELECT sname FROM s, sc WHERE s.sno=sc.sno AND grade<60 D: SELECT sname FROM s, sc WHERE s.sno=sc.sno OR grade<60

    • 4

      查询选修了课程号为'C2'的学生号和姓名,若用下列SQL的SELECT语句表达时,哪一个是错误的?() A: SELECT S#,SNAME FROM S WHERE S# = (SELECT SS# FROM SC WHERE C# = 'C2' ) B: SELECT S#,SNAME FROM S,SCWHERE S# = SS# AND C# = 'C2' C: SELECT S#,SNAME FROM S,SC WHERE S# = SS# AND C# = 'C2' ORDER BY S# D: SELECT S#,SNAME FROM S WHERE S# IN (SELECT SS# FROM SC WHERE C# ='C2' )