我是SQL的新手.我希望你能帮助我.
我需要显示每个对象的数量,以及其中有多少具有红色和蓝色.(如下表)
Objectname | totalQuantity | Quantity red | Quantity blue
----------------------------------------------------------
Object A | 22 | 10 | 12
Object B | 11 | 9 | 2
Object C | 14 | 5 | 9
例如,有22个对象A. 10个对象A的颜色为红色,另外12个对象A的颜色为蓝色.
我有以下SQL代码:
SELECT count(object_id) AS totalQuantity
FROM mytable
WHERE projectname='ProjectOne' AND projectleader='Mr.Smith'
GROUP BY Objectname
mytable中:
Object_id | Objectname | color | projectname | projectleader
-------------------------------------------------------------
837283 | Object C | red | ProjectOne | Mr.Smith
836432 | Object A | blue | …