现要从SC表中查找缺少学习成绩(G)的学生学号(S#)和课程号(C#),正确的SQL是( ).
A: SELECT S
B: ,C
C: FROM SC WHERE G=NULL
D: SELECT S
E: ,C
F: FROM SC WHERE G IS NULL
G: SELECT S
H: ,C
I: FROM SC WHERE G=0
J: SELECT S
K: ,C
L: FROM SC WHERE G<=0
A: SELECT S
B: ,C
C: FROM SC WHERE G=NULL
D: SELECT S
E: ,C
F: FROM SC WHERE G IS NULL
G: SELECT S
H: ,C
I: FROM SC WHERE G=0
J: SELECT S
K: ,C
L: FROM SC WHERE G<=0
举一反三
- 现要从SC表中查找缺少学习成绩(G)的学生学号(S#)和课程号(C#)，正确的SQL是 A: SELECT S#，C# FROM SC WHERE G=0 B: SELECT S#，C# FROM SC WHERE G<=0 C: SELECT S#，C# FROM SC WHERE G=NULL D: SELECT S#，C# FROM SC WHERE G IS NULL
- 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语句为（ ）。 A: select S B: from sc where C C: =‘C2’and grade>= (select grade from sc where C D: =‘C2’) E: select S F: 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 from 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’)
- 检索选修“C2”课程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 F: 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 FORM sc WHERE c L: =’C2’); M: SELECT s N: FROM sc WHERE c O: =’C2’ AND grade＞＝(SELECT max(grade) FROM sc WHERE c P: =’C2’);
- 假设有三个基本表：学生表S、课程表C、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）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 F: 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 FROM 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”)
- 检索选修课程号为“D3”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 C: WHERE C#='D3'AND GRADE＞= D: (SELECT GRADE FROM SC E: WHERE C#='D3')； F: SELECT S# G: FROM SC H: WHERE C#='D3'AND GRADE IN I: (SELECT GRADE FROM SC J: WHERE C#='D3')； K: SELECT S# L: FROM SC M: WHERE C#='D3'AND GRADE NOT IN N: (SELECT GRADE FROM SC O: WHERE C#='D3')； P: SELECT S# Q: FROM SC R: WHERE C#='D3'AND GRADE＞=ALL S: (SELECT GRADE FROM SC T: WHERE C#='D3')；