突维

show databases;-- `显示所有的库`use koa2weibo;-- `启用当前的库` select * from blog order by id desc; //通过id 倒序查询select * from users; //查询users表 所有数据 一般不用 而用下面条件查询select username,`password` from users where username='aaa' and `password`='123'; //条件查询-- selec.