第1题:
第( 36 ) - ( 37 )题基于学生一选课一课程数据库中的三个基本表:
学生信息表: STUDENT ( sno, sname, sex, age, dept ) 主码为 sno
课程信息表: CDLIRSB ( cno, cname, teacher ) 主码为 cno
学生选课信息表: SC ( sno, cno, grade ) 主码为( sno, cno )
( 36 )“ 查询没有学习成绩的学生的学号和课程号 ” 的 SQL 语句是
A ) SELECT snc, cno FROM SC WHERE grade=NULL
B ) SELECT sno, cno FROM SC WHERE grade IS' '
C ) SELECT sno. cno FROM SC WHERE grade IS NULL
D ) SELECT sno. cno FROM SC WHERE grade =' '
第2题:
在关系SC中,查询学习课程号为′DB′,且成绩在60至90之间的学生学号的正确的 SQL命令是
A.SELECT SNO FROM SC WHERE CNO=′DB′AND GRADE DETWEEN 60 AND 90
B.SELECT SNO FROM SC WHERE CNO=′DB′OR GRADE BETWEEN 60 AND 90
C.SELECT SNO FROM SC WHERE CNO=′DB′AND GRADE>=60 AND 90
D.SELECT SNO FROM SC WHERE CNO=′DB′AND GRADE<=60 AND GRADE>=90
第3题:
(40)查找学生姓名及其所选修课程号和成绩,正确的 SQL 语句是
A)SELECT sname FROM student, SELECT cno,grade FROM sc WHERE student.sno =sc.sno
B) FROM sname,cno,grade FROM student,course WHERE student.sno =course.cno
C) SELECT sname ,canme,grade FROM student,course,sc WHERE student.sno =sc.sno and sc.c
no=course.cno
D) SELECT sname ,cno,grade FROM student,sc WHERE student.sno =sc.sno
第4题:
有如下的SOL语句:
Ⅰ.SELECT sname FROM s,sc WHERE grade<60
Ⅱ.SELECT sname FROMs WHERE sno IN (SELECT sno FROM sc WHERE grade<60)
Ⅲ.SELECT sname FROM s,sc WHERE s.sno=Sc.sno AND grade<60若要查找分数(grade)不及格的学生姓名(sname),
以上正确的有哪些? ( )
A.Ⅰ和Ⅱ
B.Ⅰ和Ⅲ
C.Ⅱ和Ⅲ
D.Ⅰ、Ⅱ和Ⅲ
第5题:
基于学生.课程数据库中的三个基本表:
学生信息表:s (snumber, sname, sex, age, dept)主码为snumber
课程信息表:c(cnumber, cname,teacher)主码为cnumber
学生选课信息表:sc(snumber, cnumber, grade)主码为(snumber, cnumber)
“从学生选课信息表中找出无成绩的元组”的SQL语句是( )。
A)SELECT ﹡FROM sc WHERE grade=NULL
B)SELECT﹡FROM sc WHERE grade IS "
C)SELECT﹡FROM sc WHERE grade IS NULL
D)SELECT﹡FROM sc WHERE grade=''
第6题:
有如下的SQL语句: Ⅰ. SELECT sname FROM s, sc WHERE grade60 Ⅱ. SELECT sname FROM s WHERE sno IN(SELECT sno FROM sc WHERE grade60) Ⅲ. SELECT sname FROM s, sc WHERE s.sno=sc.sno AND grade60 若要查找分数(grade)不及格的学生姓名(sname),以上正确的有哪些?( )。
A.Ⅰ和Ⅱ
B.Ⅰ和Ⅲ
C.Ⅱ和Ⅲ
D.Ⅰ、Ⅱ和Ⅲ
第7题:
已知关系模式:sc(sno, sname, grade),各属性含义依次为学号、课程名、分数。要查找“数据库”课分数最高的学生的学号,正确的SQL语句是
A.SELECT sno FROM sc WHERE sname="数据库" AND grade=MAX(grade)
B.SELECT sno FROM sc FOR sname="数据库" OR grade>=MAX(grade)
C.SELECT sno FROM sc WHERE sname="数据库" AND grade=(SELECT MAX(grade) FROM sc
D.SELECT sno FROM sc FOR sname="数据库" OR grade=(SELECT MAX (grade) FROM sc
第8题:
在关系SC中,查询学习课程号为\'DB\',且成绩在60至90之间的学生学号的正确的SQL命令是( )。
A.SELECT SNO FROM SC WHERE CNO='DB'AND GRADE BETWEEN 60 AND 90
B.SELECT SNO FROM SC WHERE CN0='DB' 0R GRADE BETWEEN 60 AND 90
C.SELECT SNO FROM SC WHERE CNO='DB'AND GRADE>=60 AND 90
D.SELECT SNO FROM SC WHERE CNO='DB'AND GRADE<=60 AND GRADE>=90
GRADE BETWEEN 60 AND 90等价于GRADE>=60 AND GRADE<=90。
第9题:
已知学生选课信息表:sc(sno,cno,grade)。查询“至少选修了一门课程,但没有学习成绩的学生学号和课程号”的SQL语句是
A.SELECT sno,cno FROM sc WHERE grade=NULL
B.SELECT sno,cno FROM sc WHERE grade IS‘’
C.SELECT sno,cno FROM sc WHERE grade IS NULL
D.SELECT sno,cno FROM sc WHERE grade=‘’
第10题:
“从学生选课信息表中找出无成绩的元组”的SQL语句是( )。 A.SELECT*FROM sc WHERE grade=NULL B.SELECT*FROM sc WHERE grade IS'' C.SELECT*FROM sc WHERE grade IS NULL D.SELECT*FROM sc WHERE grade=''