非相关子查询
eg列出没学过李明老师讲授课程的所有同学的姓名?7.8:24
Select Sname
From Student
Where Sno not in (Select Sno From SCWhere Cno not in (Select CnoFrom TeacherWhere Tname 李明)
)UP is wrong!
Select Sname
From Student
Where Sno not…
文章目录 Reference数据集分类What is cross validationKNN相比1-NN的好处 Reference
https://zhuanlan.zhihu.com/p/20900216
数据集分类
training settest setvalidation set
当dataset数量过少,使用交叉验证的方法来进行超参数tuning。
What is cross valid…
php企业建站源码 1 <?php2 session_start();3 include "./admin/config.php";4 include "./right/sql.php";5 ?>6 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-t…
在做移动端web app的时候,众所周知,移动设备分辨率五花八门,虽然我们可以通过CSS3的media query来实现适配,例如下面这样: 1 html {2 font-size : 20px;3 }4 media only screen and (min-width: 401px…