请教大神怎么解决sql中多个select合并问题

SELECT months, total, ruzhu, cancels
FROM (SELECT to_char(ordertime,'mm') as months,count(*) as total, 0 ruzhu, 0 cancels
FROM tb_order where B_ID = '1'
GROUP BY to_char(ordertime,'mm')

UNION ALL

SELECT to_char(ordertime,'mm') as months, 0 total, count(*) as ruzhu, 0 cancels
FROM tb_order where B_ID = '1' and (status = 1 or status = 2 or status = 3)
GROUP BY to_char(ordertime,'mm')

UNION ALL

SELECT to_char(ordertime,'mm') as months, 0 total, 0 ruzhu, count(*) as cancels
FROM tb_order where B_ID = '1' and (status = 6 or status = 7)
GROUP BY to_char(ordertime,'mm'))
查询结果如下图

我想想要的结果是
moths total ruzhu cancels

08 1 1 0
07 7 5 2

把你的查询语句用select包起来，然后按月份分组
select sum(a.total) total, sum(a.ruzhu) ruzhu, sum(a.cancels) cancels from ( 你的sql ) a group by a.months

再上面的基础上 再包一层select 查询 再进行group by

再上面的基础上 再包一层select 查询 再进行group by

我觉得你的Sql这样写比较好
SELECT to_char(ordertime,'mm') as months,
sum(case when status = 1 or status = 2 or status = 3 or status = 6 or status = 7 then 1 else 0 end) total,
sum(case when status = 1 or status = 2 or status = 3 then 1 else 0 end) ruzhu,
sum(case when status = 6 or status = 7 then 1 else 0 end) cancels
FROM tb_order
where B_ID = '1'
GROUP BY to_char(ordertime,'mm')