对于学生信息表:student(sno,sname,sex,age,dept),要查询所有刘姓学生的信息,正确的语句是
A:SELECT * FROM student WHERE sname LIKE'刘 * ' B:SELECT * FROM student WHERE sname LIKE'刘 $' C:SELECT * FROM student WHERE sname LIKE'刘%' D:SELECT * FROM student WHERE sname LIKE'刘&'
~(24)第(23)~(24)题基于以下说明。设有三个关系:
学生关系S(SNO,SNAME,AGE,SEX)(分别代表学生的学号、姓名、年龄、性别)
学习关系SC(SNO,CNO,GRADE)(分别代表学生的学号、课程编号、成绩)
若在关系S中查找姓名中第一个字为’王’的学生的学号和姓名。下面列出的SQL语句中,正确的是
A:SELECT SNO,SNAME FROMSWHERE SNAME=’王%’ B:SELECT SNO,SNAME FROM S WHERE SNAME=’王_’ C:SELECT SNO,SNAMEFROMS WHERE SNAME LIKE ’王%’ D:SELECT SNO,SNAME FROM S WHERE SNAME LIKE ’王_’
以下三题基于"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)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.S#,SNAME FROM S WHERE S.S#=(SELECT SC.S# FROM SC WHERE C#=’C2’) B:SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#=’C2’ C:SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#=’C2’ ORDER BY S.S# D:SELECT S.S#,SNAME FROM S WHERE S.S# IN (SELECT SC.S# FROM SC WHERE C#=’C2’)
在“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)
查询选修了课程号为“C1”的学生的姓名和年龄,若用下列SQL的SELECT语句表达时,哪一个是错误的
A:SELECT SNAME,AGE FROM S WHERE B:S.S#
=(SELECT S C:S# FROM SC WHERE D:C#='C1') E:SELECT SNAME,AGE FROM S,SC
WHERE F:S.S#=S G:S# AND S H:C#='C1' I:SELECT SNAME,AGE FROM S,SC
WHERE J:S.S#=S K:S# AND S L:C#='C1'ORDER BY M:S.S# N:SELECT SNAME,AGE FROM S WHERE
以下三题基于"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)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.S#,SNAME FROM S WHERE S.S#=(SELECT SC.S# FROM SC WHERE C#=’C2’) B:SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#=’C2’ C:SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#=’C2’ ORDER BY S.S# D:SELECT S.S#,SNAME FROM S WHERE S.S# IN (SELECT SC.S# FROM SC WHERE C#=’C2’)
~(24)第(23)~(24)题基于以下说明。设有三个关系:
学生关系S(SNO,SNAME,AGE,SEX)(分别代表学生的学号、姓名、年龄、性别)
学习关系SC(SNO,CNO,GRADE)(分别代表学生的学号、课程编号、成绩) |
若在关系S中查找姓名中第一个字为’王’的学生的学号和姓名。下面列出的SQL语句中,正确的是
A:SELECT SNO,SNAME FROMSWHERE SNAME=’王%’ B:SELECT SNO,SNAME FROM S WHERE SNAME=’王_’ C:SELECT SNO,SNAMEFROMS WHERE SNAME LIKE ’王%’ D:SELECT SNO,SNAME FROM S WHERE SNAME LIKE ’王_’
以下三题基于"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)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.S#,SNAME FROM S WHERE S.S#=(SELECT SC.S# FROM SC WHERE C#=’C2’) B:SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#=’C2’ C:SELECT S.S#,SNAME FROM S,SC WHERE S.S#=SC.S# AND C#=’C2’ ORDER BY S.S# D:SELECT S.S#,SNAME FROM S WHERE S.S# IN (SELECT SC.S# FROM SC WHERE C#=’C2’)