题目内容
（请给出正确答案）
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
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更多“根据SQL标准，创建一个表，应该使用下面哪个语句？（)A C…”相关的问题
A.CreateTable
B.AlterTable
C.CreateIndex
D.CreateDatabase
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，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
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
T.对
F.错
编写SQL代码，创建这些表。指定哪些列不能是NULL，并且指定主键和外键约束。 注意：假设Deliveries表中的Delivery_Service列具有与Delivery_Services表中的Name列相同的含义。
