单项选择题
设数据库中已有教材中的Student(Sno,Sname,Ssex,Sage,Sdept)、Course(Cno,Cname,Credit,Semster)和SC(Sno,Cno,Grade)表。现要查询学生选的第2学期开设课程的情况,只需列出学号、姓名、所在系和所选的课程号。该查询涉及到的表是()。
A.仅Student表
B.仅Student和SC表
C.仅Student和Course表
D.Student、SC和Course表
相关考题
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单项选择题
设有Teachers表,该表的定义如下: CREATE TABLE Teachers( Tno CHAR(8) PRIMARY KEY, Tname VARCHAR(10) NOT NULL, Age TINYINT CHECK(Age BETWEEN 25 AND 65) ) 下列插入语句中,不能正确执行的是()。
A.INSERT INTO Teachers VALUES(’T100’,’张宏’,NULL)
B.INSERT INTO Teachers(Tno,Tname,Age) VALUES(’T100’,’张宏’,30)
C.INSERT INTO Teachers(Tno,Tname) VALUES(’T100’,’张宏’)
D.INSERT INTO Teachers VALUES(’T100’,’张宏’) -
单项选择题
下列SQL语句中,用于修改表数据的语句是()。
A.ALTER
B.SELECT
C.UPDATE
D.INSERT -
单项选择题
设SC表中记录成绩的列为:Grade,类型为int。若在查询成绩时,希望将成绩按‘优’、‘良’、‘中’、‘及格’和‘不及格’形式显示,正确的Case函数是()。
A. Case Grade When 90~100 THEN ’优’ When 80~89 THEN ’良’ When 70~79 THEN ’中’ When 60~69 THEN ’及格’ Else ’不及格’ End
B. Case When Grade between 90 and 100 THEN Grade = ’优’ When Grade between 80 and 89 THEN Grade = ’良’ When Grade between 70 and 79 THEN Grade = ’中’ When Grade between 60 and 69 THEN Grade = ’及格’ Else Grade = ’不及格’ End
C. Case When Grade between 90 and 100 THEN ’优’ When Grade between 80 and 89 THEN ’良’ When Grade between 70 and 79 THEN ’中’ When Grade between 60 and 69 THEN ’及格’ Else ’不及格’ End
D.Case Grade When 90~100 THEN Grade = ’优’ When 80~89 THEN Grade = ’良’ When 70~79 THEN Grade = ’中’ When 60~69 THEN Grade = ’及格’ Else Grade = ’不及格’ End
