复杂的联合查询

Question

select
    equip,
    count_1 = sum(decode(type,1,1,0)),
    count_2 = sum(decode(type,1,2,0)),
    count_3 = sum(decode(type,1,3,0))
from
    表
group by
    equip

Answer 1

在楼上写错了，汗ingselect
    equip,
    count_1 = sum(decode(type,1,1,0)),
    count_2 = sum(decode(type,2,1,0)),
    count_3 = sum(decode(type,3,1,0))
from
    表
group by
    equip

Answer 2

select
    equip,
    sum(decode(type,1,1,0)) count_1,
    sum(decode(type,2,1,0)) count_2,
    sum(decode(type,3,1,0)) count_3
from
    表
group by
    equip