在选择时,有没有简单的技巧可以将排序顺序改为“先是字符值升序,然后是数值升序”? SELECT mycol
FROM mytable
ORDER BY mycol 结果: 1C
8Q
9G
AR
BZ
IT 使用DESC: SELECT mycol
FROM mytable
ORDER BY mycol DESC 结果: IT
BZ
AR
9G
8Q
1C 预期结果: AR
BZ
IT
1C
8Q
9G
我从Software收到以下错误消息:
The upgrade needs a total of 74,6 M free space on disk '/boot'. Please free at least an additional 68,3 M of disk space on '/boot'. Empty your trash and remove temporary packages of former installations using 'sudo apt-get clean'.
怎样才能获得更多的光盘空间?我有过
df -h
F
尝试使用Kubuntu 16.04 64位版本安装redis服务器,使用:
sudo apt install redis-server
但在安装时接收此消息:
Setting up redis-server (2:3.0.7-1~dotdeb+6.1) ...
Job for redis-server.service failed because a timeout was exceeded. See "systemctl status redis-server.service" and "journalctl -xe" for details.
invoke-