select sum(case
when con1 = 1 and con2 = 1 then
count
else
0
end) 三星笔记本,
sum(case
when con1 = 1 and con2 = 2 then
count
else
0
end) 三星台式机,
sum(case
when con1 = 2 and con2 = 1 then
count
else
0
end) 苹果笔记本,
sum(case
when con1 = 2 and con2 = 2 then
count
else
0
end) 苹果台式机
from table_name;
select sum(case when con1||con2='11' then count else 0 end) 三星笔记本,
sum(case when con1||con2='12' then count else 0 end) 三星台式机,
sum(case when con1||con2='22' then count else 0 end) 苹果笔记本,
sum(case when con1||con2='22' then count else 0 end) 苹果台式机
from table_name
另外用decode一样可以替代case when,效率一样
select case when t.con1=1 and t.con2=1 then t.count else 0 end as '三星笔记本'，
case when then else end from 表名字 t
就照这样写
group by 按 con1 con2 分组 然后sum
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024