有关系S(S#,SNAME,SAGE),C(C#,CNAME),SC(S#,C#,GRADE)。要查询选修“ACCESS”课的年龄不小于20的全体学生姓名的SQL语句是“SELECT SNAME FROM S,C,SC WHERE子句”。这里的WHERE子句的内容是()。
A. S.S
B. =SC.S
C. AND C.C
D. =SC.C
E. AND SAGE>=20 AND CNAME='ACCESS'
F. S.S
G. =SC.S
H. AND C.C
I. =SC.C
J. AND SAGE IN >=20 AND CNAME IN 'ACCESS'
K. SAGE>=20 AND CNAME='ACCESS'
L. SAGE>=20 AND CNAME IN 'ACCESS'
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有如下的SQL语句:Ⅰ. SELECT sname FROM s, sc WHERE grade<60Ⅱ. SELECT sname FROM s 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),则以上正确的有哪些?()
A. Ⅰ和Ⅱ
B. Ⅰ和Ⅲ
C. Ⅱ和Ⅲ
D. Ⅰ、Ⅱ和Ⅲ
基于这样的3个表,即学生表S、课程表C和学生选课表SC,它们的关系模式如下:S(S#,SN,SEX,AGE,DEPT)(学号,姓名,性别,年龄,系别)C(C#,CN)(课程号,课程名称)SC(S#,C#,GRADE)(学号,课程号,成绩).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 S
B. FROM SC WHERE C
C. =C2 AND GRADE>=(SELECT GRADE FROM SC WHERE C
D. ='C2')
E. SELECT S
FROM SC WHERE C
G. =C2 AND GRADE IN(SELECT GRADE FROM SC WHERE C
H. ='C2')
I. SELECT S
J. FROM SC WHERE C
K. =C2 AND GRADE NOT IN (SELECT GRADE GORM SC WHERE C
L. ='C2')
M. SELECT S
N. FROM SC WHERE C
O. =C2 AND GRADE>=ALL(SELECT GRADE FROM SC WHERE C
P. ='C2')
现有学生表S、课程表C和学生选课表SC,它们的关系模式如下。S(S#,SN,SEX,AGE,DEPT)(学号,姓名,性别,年龄,系别);C(C#,CN)(课程号,课程名称);SC(S#,C#,GRADE)(学号,课程号,成绩)。检索所有比“王华”年龄大的学生姓名、年龄和性别。下面正确的SELECT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 SGE>'王华'.AGE
能实现查询sell表中尚未发货的订单记录的语句是()。
A. SELECT * FROM sell WHERE 是否发货=NULL;
B. SELECT * FROM sell WHERE 是否发货 IS NULL;
C. SELECT * FROM sell WHERE 是否发货IS NOT NULL;
D. SELECT * FROM sell ORDER BY 是否发货;
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