A: Select sno , cno from sc where grade < > null
B: Select sno as 学号, cno as 课程号 from sc where grade is not null
C: Select sno , cno from sc where grade !=‘ ’
D: Select sno , cno from sc where grade is not null
举一反三
- “查询没有学习成绩的学生的学号和课程号”的SQL语 句是( ) (2.0) 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 = ' '
- 下列SQL语句中，________可以在“学生-课程”数据库中实现“查询所有有成绩的学生学号和课程号”。 A: SELECT Sno，Cno FROM SC WHERE Grade <> NULL B: SELECT Sno，Cno FROM SC WHERE Grade NOT NULL C: SELECT Sno，Cno FROM SC WHERE Grade >0 D: SELECT Sno，Cno FROM SC WHERE Grade IS NOT NULL
- 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=
- 检索选修了课程”C1”的学生中成绩最高的学生的学号，正确的SELECT语句为（ ） A: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE >=ALL (SELECT Grade FROM SC WHERE Cno=’C1’); B: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE IN (SELECT Grade FROM SC WHERE Cno=’C1’); C: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE > ANY (SELECT Grade FROM SC WHERE Cno=’C1’); D: SELECT Sno FROM SC WHERE Cno=’C1’ AND GRADE >= (SELECT Grade FROM SC WHERE Cno=’C1’);
- 检索选修课程“C2”的学生中成绩最高的学生的学号。正确的SELECT语句是（）。 A: SELECT SNO FROM SC WHERE CNO='C2' AND GRADE >= ( SELECT GRADE FORM SC WHERE CNO='C2' ); B: SELECT SNO FROM SC WHERE CNO='C2' AND GRADE IN ( SELECT GRADE FORM SC WHERE CNO='C2' ); C: SELECT SNO FROM SC WHERE CNO='C2' AND GRADE NOT IN ( SELECT GRADE FORM SC WHERE CNO='C2' ); D: SELECT SNO FROM SC WHERE CNO='C2' AND GRADE >= ALL ( SELECT GRADE FORM SC WHERE CNO='C2' );
内容
- 0
基于学生—选课—课程数据库中的三个基本表：学生的信息表：STUDENT(sno, sname, sex, age, dept)主码为sno课程信息表：COURSE(cno,cname, teacher)主码为cno学生选课信息表：SC(sno, cno, grade)主码为(sno, cno) “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 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="
- 1
查询编号为'c01'的课程考试成绩在80-89之间的学生的学号,下列（）语句不能实现。 A: select sno ,grade from sc where cno='c01' and grade between 80 and 89 B: select sno ,grade from sc where cno='c01' and grade>=80 and grade<90 C: select sno ,grade from sc where cno='c01' and not (grade90) D: select sno ,grade from sc where cno='c01' and grade in (80-89)
- 2
查询选课关系SC(Sno,Cno,Score)表中还没有给定成绩()的课程号()和学号(),下列语句正确的是。() A: SELECT<br/>Sno,Cno<br/>FROM SC WHERE Score IS NULL B: SELECT*<br/>FROM SC WHERE Score =NULL C: SELECT<br/>Sno,Cno<br/>FROM SC D: SELECT<br/>Score FROM SC WHERE Sno,Cno<br/>IS NOT NULL
- 3
有关系S(SNO, SNAME, SAGE)，C(CNO, CNAME)，SC(SNO, CNO, GRADE)。其中SNO是学生号，SNAME是学生姓名，SAGE是学生年龄， CNO是课程号，CNAME是课程名称，GRADE是成绩。以下（ ）SQL语句可以实现查询选修了'C002'号课程的学生姓名。 A: SELECT SNAME FROM S, SC WHERE S.SNO=SC.SNO AND CNO='C002' B: SELECT SNAME FROM S WHERE SNO IN (SELECT SNO FROM SC WHERE CNO='C002') C: SELECT SNAME FROM S WHERE SNO = (SELECT SNO FROM SC WHERE CNO='C002') D: SELECT SNAME FROM S WHERE SNO NOT IN (SELECT SNO FROM SC WHERE CNO='C002')
- 4
若查询考试成绩不为空的学生的学号，下列语句哪个是正确的？（ ） A: SELECT Sno FROM SC WHERE Grade >= 0； B: SELECT Sno FROM SC WHERE Grade ！= 0； C: SELECT Sno FROM SC WHERE Grade IS NOT NULL； D: SELECT Sno FROM SC WHERE Grade NOT IS NULL；