sql - Row_Number() 继续联合所有查询

Question

如果我有 3 个表，如何获得增量唯一编号？

例如:

第一个查询 row_number 结果 = 1,2,3

第二个查询 row_number 结果 = 4,5,6

第三次查询 row_number 结果 = 7,8,9

我尝试了下面的查询，但从中我可以得到第二个表的增量。

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

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

Answer 1

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;