如何在同一查询中获取带有行号的 MAX 行号

Question

我在 sql 语句中有 ROW_NUMBER() OVER (ORDER BY NULL) rnum 给我行号。有没有办法将最大 rnum 附加到同一个数据集？

我想要的是我得到的 row_number()，但我还想要每条记录上总 return 的最大行数。

    SELECT 
    ROW_NUMBER() OVER (ORDER BY NULL) rnum,
    C.ID, C.FIELD1, C."NAME", C.FIELD2, C.FIELD3
    FROM SCHEMA.TABLE 
    WHERE (C.IS_CRNT = 1)
), MAX_NUM as (
    SELECT DATA.ID, max(rnum) as maxrnum from DATA GROUP BY DATA.COMPONENT_ID
) select maxrnum, DATA.* from DATA JOIN MAX_NUM on DATA.COMPONENT_ID = MAX_NUM.COMPONENT_ID

期望的结果（假设 15 条记录）：

1     15    DATA
2     15    DATA
3     15    DATA
etc...

Answer 1

我想你想要 count(*) 作为 window 函数：

SELECT ROW_NUMBER() OVER (ORDER BY NULL) as rnum,
       COUNT(*) OVER () as cnt,
       C.ID, C.FIELD1, C."NAME", C.FIELD2, C.FIELD3
FROM SCHEMA.TABLE 
WHERE C.IS_CRNT = 1

Answer 2

根据我在您的数据集中的假设，我将采用以下方法：

WITH CTE AS (
select C.ID, C.FIELD1, C."NAME", C.FIELD2, C.FIELD3, ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ID)
FROM SCHEMA.TABLE WHERE (C.IS_CRNT = 1))
SELECT *, (select count(*) from cte) "count" from cte;

如何在同一查询中获取带有行号的 MAX 行号

How to get MAX rownumber with rowNumber in same query

sql

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