1, the view definition
View may allow a query to save, and to treat the query as table operation, the view is a logical structure, and does not store data.
2, create a view
To restrict data access by creating a view that can be used to protect information from being random queries.
create table userinfo（
id int，name string，age int，address string
）；
create view some_userinfo as
select id，name from userinfo；
3. Delete View
drop view if exists userinfo；
4, knowledge about the view
show tables you can see the view, you can not use insert and load commands to manipulate the view.
View is read-only, the operation of the operation metadata are views.