Row_Number() 继续联合所有查询

Row_Number() continue in Union all query

如果我有 3 个 table,我如何获得增量唯一编号?

例如:

我尝试了下面的查询,但从中我可以获得增量到第 2 个 table。

SELECT ROW_NUMBER() OVER(ORDER BY filename) AS SrNo,fileName FROM Tab1
UNION ALL
SELECT ROW_NUMBER() OVER(ORDER BY filename) + (SELECT COUNT(*) FROM tab1) AS 
SrNo, filename FROM Tab2
UNION ALL
SELECT ROW_NUMBER() OVER(ORDER BY filename) + (SELECT COUNT(*) FROM tab2) AS 
SrNo, filename FROM Tab3

每个 table 有 3 条记录,我想得到 row_number 的结果为 1,2,3,4,5,6,7,8,9

使用子查询:

SELECT ROW_NUMBER() OVER (ORDER BY which, filename) as SrNo, filename
FROM (SELECT 1 as which, fileName FROM Tab1
      UNION ALL
      SELECT 2 as which, filename FROM Tab2
      UNION ALL
      SELECT 3 as which, filename FROM Tab3
     ) ttt;