Sql 如何包含作为列值返回的总行数？

Oracle 11g

我希望将max（rownum）作为一个新列包含进来，以获得所需的结果。本质上，我想将这个QueryA的结果作为一个新列添加到QueryB。当我在QueryB中包含max（rownum）时，我得到了一个'not a single group函数。当我按可乐或rownum分组时，QueryB也不起作用

QueryA

with data_row as
(
select 1 as col_a from dual union all
select 2 as col_a from dual union all 
select 3 as col_a from dual )
select max(rownum) as max_row from data_row

QueryB

with data_row as
( select 1 as col_a from dual union all
  select 2 as col_a from dual union all
  select 3 as col_a from dual)
select col_a, rownum from data_row

期望的结果

Col_a    Rownum   MaxRowNum
--------------------------------
1          1       3
2          2       3
3          3       3

---

您可以使用

count

函数的分析形式

SQL> ed
Wrote file afiedt.buf

  1  with data_row as (
  2    select 1 as colA from dual union all
  3    select 2 as cola from dual union all
  4    select 3 as cola from dual
  5  )
  6  select colA, rownum, count(*) over () cnt
  7*   from data_row
SQL> /

      COLA     ROWNUM        CNT
---------- ---------- ----------
         1          1          3
         2          2          3
         3          3          3

---

@PM77-1-为什么我们需要使用

SUM

？你认为我们需要做什么来求和？听起来目标似乎是确定结果集中的行数，因此

COUNT

似乎是一个明智的选择。实际上我考虑的是MAX，但即使这样也是错误的。请不要理会我的评论。