根据SQL标准,要创建唯一索引该使用下面哪种语句?()A CREATE UNIQUE INDEXB CREATE CLUSTER IN
根据SQL标准,要创建唯一索引该使用下面哪种语句?()
A CREATE UNIQUE INDEX
B CREATE CLUSTER INDEX
C CREATE ONLY INDEX
D CREATE PRIMARY INDEX
根据SQL标准,要创建唯一索引该使用下面哪种语句?()
A CREATE UNIQUE INDEX
B CREATE CLUSTER INDEX
C CREATE ONLY INDEX
D CREATE PRIMARY INDEX
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,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,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
A create view abc as select * from student where dept=’IS’
B create view abc as select * from student where dept=’IS’ with check option
C create view abc as student where dept=’IS’
D create view abc as select dept=’IS’ from student
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,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,删除表student中对字段sno的唯一性约束,应该使用下面哪条语句? ()
A drop sno from table student
B alter table student drop sno
C alter table student drop unique(sno)
D alter table student drop sno unique