SQL VIEW 视图
1、语法:CREATE VIEW 视图名称 AS SELECT 列名 FROM 表名 WHERE 列名 = 值 图中为student表中的数据

2、创建视图:CREATE VIEW ageOrder AS SELECT * FROM student WHERE age > 18

3、视图创建成功在数据库中的视图就能看到ageOrder视图

4、查询视图SELECT * FROM ageorder

5、更新视图:年龄大于20岁的学生CREATE OR REPLACE VIEW ageorder AS SELECT * FROM student WHERE age > 20

6、查询视图SELECT * FROM ageorder

7、删除视图DROP VIEW ageorder
