根据SQL标准,修改表的数据结构,下面哪种语句适用?()A UPDATEB ALTERC CHANGED SHIFT
根据SQL标准,修改表的数据结构,下面哪种语句适用?()
A UPDATE
B ALTER
C CHANGE
D SHIFT
根据SQL标准,修改表的数据结构,下面哪种语句适用?()
A UPDATE
B ALTER
C CHANGE
D SHIFT
根据SQL标准,要修改表student中所有学生的年龄age,使之在原值基础上减一,下面哪个语句适用?()
A update student set age = 1
B update student set age = age - 1
C update age = age -1 from student
D update from student where age = age -1
根据SQL标准,创建一个表,应该使用下面哪个语句?()
A CREATE TABLE
B CREATE INDEX
C CREATE VIEW
D CREATE DATABASE
根据SQL标准,删除一个表,应该使用下面哪个语句?()
A DELETE TABLE
B DROP TABLE
C DELETE VIEW
D DROP DATABASE
根据SQL标准,查询表student(sno,sname,sex,dept)中所有学生的选修课程数,其中选修记录在表SC(sno,cno,grade)中,两表中sno为关联字段。下面哪条语句合适?()
A select sno,count(cno) from SC
B select sno,count(cno) from student
C select a.sno,count(cno) from student a left outer join SC
D select a.sno,count(cno) from SC left outer join student a
A select dept,avg(age) from student where avg(age)<21
B select dept,avg(age) from student group by dept having avg(age)<21
C select dept,avg(age) from student having avg(age)<21
D select dept,avg(age) from student group by dept where avg(age)<21
A insert into student sdate char(7)
B add sdate char(7) to student
C append sdate varchar(7) to table student
D alter table student add sdate varchar(7)
E alter table student add sdate char(7)
F alter table student modify sdate char(7)
A insert into student values(sno=11301, sname=’snoopy’, age =20)
B insert into student(sno,sname,age) values(11301,’snoopy’,20)
C insert into student set sno=11301, sname=’snoopy’, age = 20
D insert into student values (11301, ’snoopy’, 20)
根据SQL标准,删除索引应该选用下面哪个语句?()
A DELETE INDEX
B DROP INDEX
C DELETE VIEW
D DROP VIEW
根据SQL标准,创建一个视图,应该使用下面哪个语句?()
A CREATE TABLE
B CREATE INDEX
C CREATE VIEW
D CREATE DATABASE
根据SQL标准,下面哪条语句与select min(age) from student等效?()
A select age from student where age >= min(age)
B select distinct age from student where age >= all min(age)
C select distinct a.age from student a where a.age<= any (select distinctb.age from student b)
D select distinct a.age from student a where a.age<= all (select distinct b.age from student b)