over的功能:一、with Ta as(select 1 as Fa, a as Fbunion allselect 2 as Fa, b as Fbunion allselect 3 as Fa, c as Fbunion allselect 4 as Fa, d as Fbunion allselect 5 as Fa, e as Fb)select FB ,1.*Fa/(select sum(Fa) from Ta)from Tawith Ta as(select 1…
SD卡容量的大小通过NOOBS安装带有桌面和推荐软件(完整)的 Raspberry Pi OS,SD卡最小为16GB。 对于带有桌面和推荐软件的 Raspberry Pi OS 镜像安装,SD卡最小为8GB。对于安装 Raspberry Pi OS Lite,建议 SD 卡最小为4GB…
最初参与到与物联网(Internet of Things / IoT)相关的行业对话时,我对整个行业的发展充满疑问。“ 物联网”和 “万联网”(Internet of Everything)有什么区别?这场变革现今是处于启蒙阶段,亦或…