题中假定学生关系是S(S#,SN.,SEX,AGE)，课程关系是C(C#,CNAME,TEACH-ER)，学生选课关系是SC(S#,C#,GRADE)。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# FORM SCWHERE C#="C2"AND GRADE＞=(SELECT GRADE FORM SCWHERE C#="C2") B: SELECT S# FORM SCWHERE C#="C2"AND GRADE IN(SELECT GRADE FORM SC.WHERE C#="C2" C: SELECT S# FORM SCWHERE C#="C2"AND GRADE NOT IN(SELECT GRADE FORM SCWHERE C#="C2") D: SELECT S# FORM SCWHERE C#="C2"AND GRADE＞=ALL(SELECT GRADE FORM SCWHERE C#="C2")

2022-06-16

题中假定学生关系是S(S#,SN.,SEX,AGE)，课程关系是C(C#,CNAME,TEACH-ER)，学生选课关系是SC(S#,C#,GRADE)。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# FORM SCWHERE C#="C2"AND GRADE＞=(SELECT GRADE FORM SCWHERE C#="C2") B: SELECT S# FORM SCWHERE C#="C2"AND GRADE IN(SELECT GRADE FORM SC.WHERE C#="C2" C: SELECT S# FORM SCWHERE C#="C2"AND GRADE NOT IN(SELECT GRADE FORM SCWHERE C#="C2") D: SELECT S# FORM SCWHERE C#="C2"AND GRADE＞=ALL(SELECT GRADE FORM SCWHERE C#="C2")

题中假定学生关系是S(S#,SN.,SEX,AGE)，课程关系是C(C#,CNAME,TEACH-ER)，学生选课关系是SC(S#,C#,GRADE)。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# FORM SCWHERE C#="C2"AND GRADE＞=(SELECT GRADE FORM SCWHERE C#="C2")
B: SELECT S# FORM SCWHERE C#="C2"AND GRADE IN(SELECT GRADE FORM SC.WHERE C#="C2"
C: SELECT S# FORM SCWHERE C#="C2"AND GRADE NOT IN(SELECT GRADE FORM SCWHERE C#="C2")
D: SELECT S# FORM SCWHERE C#="C2"AND GRADE＞=ALL(SELECT GRADE FORM SCWHERE C#="C2")

答案：

D

举一反三

内容

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三个表学生表S、课程表C 和学生选课表SC，它们的结构如下S(S#，SN，SEX，AGE，DEPT) C(C#，CN) SC(S#，C#，GRADE) 其中：S#为学号，SN 为姓名，SEX 为性别，AGE 为年龄，DEPT 为系别，C#为课程号，CN 为课程名，GRADE 为成绩。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: ELECT S# FORM SC WHERE C#=’C2’ AND GRAD>=(SELECT GRADE FORM SC WHERE C#=’C2’) B: SELECT S# FORM SC WHERE C#=’C2’ AND GRADE IN (SELECT GRADE FORM SC WHERE C#=’C2’) C: SELECT S# FORM SC WHERE C#=’C2’ AND GRADE NOT IN (SELECT GRADE FORM SC WHERE C#=’C2’) D: SELECT S# FORM SC WHERE C#=’C2’ AND GRADE>=ALL (SELECT GRADE FORM SC WHERE C#=’C2’)
1
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的语句是______。 A: SELECT S# FORM SC B: WHERE C#="C2" AND GRADE> =(SELECT GRADE FORM SC) C: WHERE C#="C2") D: SELECT S#FORM SC E: WHERE C#="C2" AND GRADE IN(SELECT CRADE FORM SC) F: WHERE C#="C2" G: SELECT S# FORM SC H: WHERE C#="C2" AND GRADE NOT IN(SELECT GRADE FORM SC I: WHERE C#="C2" J: SELECT S# FORM SC K: WHERE C#="C2" AND CRANDE> =ALL(SELECT GRADE FORM SC L: WHERE C#="C2")
2
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# FORM SC WHERE C#=’C2’ AND GRADE>= (SELECT GRADE FORM SC WHERE C#=’CZ’) B: SELECT S# FORM SC WHERE C#=’C2’ AND GRADE IN (SELECT GRADE FORM SC WHERE C#=’C2’) C: SELECT S# FORM SC WHERE C#=’C2’ AND GRADE NOT IN (SELECT GRADE FORM SC WHERE C#=’C2’) D: SELECT S#FROM SC WHERE C#=’C2’ AND GRADE>=ALL (SELECT GRADE FROM SC WHERE C#=’C2’)
3
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: FORM SC WHERE C C: =“C2” AND GRAD>=(SELECT GRADE FORM SCWHERE C D: =“C2”) E: SELECT S F: FORM SCWHERE C G: =“C2” AND GRADE IN(SELECT GRADE FORM SCWHERE C H: =“C2”) I: SELECT S J: FORM SCWHERE C K: =“C2” AND GRADE NOT IN(SELECT GRADE FORM SCWHERE C L: =“C2”) M: SELECT S N: FORM SCWHERE C O: =“C2” AND GRADE>=ALL(SELECT GRADE FORM SCWHERE C P: =“C2”)
4
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: FORM SCWHERE C C: =‘C2’ AND GRADE>=(SELECT GRADE FORM SCWHERE C D: =‘C2’) E: SELECT S F: FORM SCWHERE C G: =‘C2’ AND GRADE IN(SELECT GRADE FORM SCWHERE C H: =‘C2’) I: SELECT S J: FORM SCWHERE C K: =‘C2’ AND GRADE NOT IN(SELECT GRADE FORM SCWHERE C L: =‘C2’) M: SELECT S N: FORM SCWHERE C O: =‘C2’ AND GRADE>=ALL(SELECT GRADE FORM SCWHERE C P: =‘C2’)