创建试图create view sex_st (视图名称)asselect xb,count(sex) as renshu from dangan group by(sex);
查询视图select * from sex_st;
修改视图select xb,count(sex) as renshu from dangan group by(sex);
删除视图drop view sex_st;
(视图的创建只对插入数据有影响)