--sql中的 where .group by 和 having 用法解析 --如果要用到group by 一般用到的就是“每这个字” 例如说明现在有一个这样的表:每个部门有多少人 就要用到分组的技术 select DepartmentID as '部门名称',COUNT(*) as '个数' from BasicDepartment group by DepartmentID --这个就是使用了group by +字段 进行了分组,其中我们就可以理解为我们按照了部门的名称ID --Depart
转:装完Centos7提示Initial setup of CentOS Linux 7 (core) 在用U盘装完CentOS后,重新开机启动后显示: Initial setup of CentOS Linux 7 (core) 1) [x] Creat user 2) [!] License information (no user will be created) (license not accepted) Please make your choice from above ['q
装完RHEL7后,重新开机启动后显示: 1) [x] Creat user 2) [!] License information (no user will be created) (license not accepted) Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: 解决方法: 输入"1",按Enter键 输入"2",按Enter键 输入
在CentOS6.5下将自带的python2.6升级到python2.7,并安装了ipython,启动ipython后显示如下信息: WARNING: IPython History requires SQLite, your history will not be saved 解决方法如下: 下载并解压sqlite包,输入命令:#wget http://www.sqlite.org/sqlite-autoconf-3071401.tar.gz#tar zxvf sqlite-autoconf-
CentOS7安装完毕,重新开机启动后显示: Initial setup of CentOS Linux 7 (core) 1) [x] Creat user 2) [!] License information (no user will be created) (license not accepted) Please make your choice from above ['q' to quit | 'c' to continue | 'r' to refresh]: 解决方法: 输入“