Question

我有一张如下表格：

id letter number
1       A      1
2       A      2
3       A      3
4       B      1
5       C      1
6       C      2

我需要计算字母A的数字，其中字母A的数字为1 OR 2.这很简单，我就明白了。但现在我需要计算id，其中字母A的数字为 AND 数字2，等等。然后每个字母都相同。所以我会得到：

letter count
A          3
C          2

我不关心B，因为计数是1.谢谢。

Answer 1

使用分析函数（PARTITION BY）和GROUP BY：

的组合

with v_data as (
select 1 id, 'A' letter, 1 num from dual union all
select 2 id, 'A' letter, 2 num from dual union all
select 3 id, 'A' letter, 3 num from dual union all
select 4 id, 'B' letter, 1 num from dual union all
select 5 id, 'C' letter, 1 num from dual union all
select 6 id, 'C' letter, 2 num from dual
)
select letter, sum(cnt1) as cnt1, sum(cnt2) as cnt2, count(*) cnt_overall from (
select v1.*, 
  sum(case when num = 1 then 1 else 0 end) over (partition by letter) as cnt1, 
  sum(case when num = 2 then 1 else 0 end) over (partition by letter) as cnt2
 from v_data v1
) 
group by letter
having sum(cnt1) > 0 and sum(cnt2) > 0

说明：

内部查询返回alls行并计算行id的出现次数
外部查询计算给定id的行数，并获取不具有值1和2的id的rid

计算列可能具有不同值的行

1 个答案: