Question

我有一个包含样本数据的下表结构（仅列出了感兴趣的列）。我希望查询返回由up_id的＃完成的bsp_id的＃。

bsp_id | up_id | status_flag
1256     15      completed
1232     1       completed
1216     15      completed
1216     1       completed
1235     1       completed

，查询结果应为

Count(bsp_id) | Count(up_id)
    1                 2
    3                 1

Answer 1

如果您的意思如下，

Count(bsp_id) | Count(up_id)
    2                 1
    3                 1

然后查询应该是：

select count(bsp_id), count(up_id) // count(up_id) will always be 1
from tbl
where status_flag = 'completed'
group by up_id

Answer 2

您需要嵌套查询。这样的事情应该有效：

内部查询：

select bsd_id, count(*) as c from mitable
where status_flag='completed' group by bsd_id

结果：

1256，1

1232，1

1216,2

1235,1

完整的查询：

select count(*), t.c from
(select bsd_id, count(*) as c from mitable
where status_flag='completed' group by bsd_id) t
group by t.c

结果：

1,2

3,1

SQL group by和aggregate函数

2 个答案: