【单选题】基于"学生-选课-课程"数据库中的三个关系: S(S#,SNAME,SEX,BIRTHYEAR,DEPT),主码为 S# C(C#,CNAME,TEACHER),主码为 C# SC(S#,C#,GRADE),主码为(S#,C# 查找"选修了至少 5 门课程的学生的学号",正确的 SQL 语句是( )。
A.
SELECT S# FROM SC GROUP BY S# HAVING COUNT(*)>=5
B.
SELECT S# FROM SC GROUP BY S# WHERE COUNT(*)>=5
C.
SELECT S# FROM SC HAVING COUNT(*)>= 5
D.
SELECT S# FROM SC WHERE COUNT(*)>=5
【单选题】《十二铜表法》制定之前,罗马贵族喜欢用习惯法裁判,主要是因为()
【判断题】The word "alliteration" means "押头韵".
【单选题】设基于"学生-选课-课程"数据库中如下三个关系:S(Sno,SNAME,SEX,AGE), SC(Sno,Cno,GRADE), C(Cno,CNAME,TEACHER)。把学生的学号及他的平均成绩定义为一个视图。定义这个视图时,所用的SELECT语句中将出现哪些子句( )?I. FROM II. WHERE III. GROUP BY IV. ORDER BY。
【单选题】基于"学生-选课-课程"数据库中的三个关系: S(S#,SNAME,SEX,BIRTHYEAR,DEPT),主码为 S# C(C#,CNAME,TEACHER),主码为 C# SC(S#,C#,GRADE),主码为(S#,C#) 查找"选修了 C01 号课程的全体学生的姓名和所在的系", 下列SQL 语句中哪一个是错误的( )。
A.
SELECT SNAME, DEPT FROM S WHERE S# IN (SELECT S# FROM SC WHERE C# ='C01')
B.
SELECT SNAME, DEPT FROM S WHERE S# = (SELECT S# FROM SC WHERE C# ='C01')
【单选题】基于"学生-选课-课程"数据库中的三个关系:S(S#,SNAME,SEX,AGE), SC(S#,C#,GRADE), C)(C#,CNAME,TEACHER),若要求查找姓名中第一个字为'王'的学生号和姓名。下面列出的SQL语句中,哪个(些)是正确的?
A.
SELECT S#,SNAME FROM S WHERE SNAME = ˊ王%ˊ
B.
SELECT S#,SNAME FROM S WHERE SNAME LIKE ˊ王%ˊ
C.
SELECT S#,SNAME FROM S WHERE SNAME LIKE ˊ王_ ˊ
【单选题】设基于"学生-选课-课程"数据库中如下三个关系:S(Sno,SNAME,SEX,AGE), SC(Sno,Cno,GRADE), C(Cno,CNAME,TEACHER)。查询选修了课程号为'C2'的学生号和姓名,若用下列SQL的SELECT语句表达时,哪一个是错误的( )?
A.
SELECT S.Sno,SNAME FROM S WHERE S.Sno= (SELECT S
B.
SELECT S.Sno,SNAME FROM S,SC WHERE S.Sno = SSn
C.
SELECT S.Sno,SNAME FROM S,SC WHERE S.Sno = SSn
D.
SELECT S.Sno,SNAME FROM S WHERE S.Sno IN (SELECT
【单选题】《十二铜表法》制定之前,罗马贵族喜欢用习惯法裁判,主要是因为习惯法
【判断题】Alliteration (头韵) Alliteration is the repetition of the same initial consonant sound within a line or a group of words. 头韵:在一组词的开头或重读音节中对相同辅音或不同元音的重复。
【单选题】Which sentence does not use alliteration(头韵)?
A.
Can we forge against these enemies a grand and global alliance....?
B.
“Pay any price, bear any burden…”
C.
For man holds in his mortal hands the power to abolish all forms of human poverty and all forms of human life.
D.
“Let us go forth to lead the land we love….”