可以先转置再算,如下:
select Site, CPU1-CPU2 as`d from select Temperature from T pivot by Site, CPU
请问一个窄表里面 , 假设存了两个站点的CPU 温度,这样,如果想横向比较,两个CPU的温度的差值,要怎么操作啊?
| Site | CPU | Temperature | |--------|-----------|---------------| | A | CPU1 | 60.0 | | A | CPU2 | 65.0 | | B | CPU1 | 70.0 | | B | CPU2 | 72.0 | | C | CPU1 | 62.0 | | C | CPU2 | 68.0 |
如果我用q来写,可以如下:
select (-). Temperature by Site from `Site`CPU xasc T