mysql一次查询，返回多个统计结果

1.sum(if)

select
sum(if(status=1,1,0)) as s1_count,
sum(if(status=2,1,0)) as s2_count
from order;

2.count()

select
count(status=1 or null) as s1_count,
count(status=2 or null) as s2_count
from order;

注意：count是返回匹配条件的行数，只要有值就会算进去，所以这里不符合条件的算作Null