sql-server - SQL Server（T-sql）从下到上更新表

Question

我试图从下到上更新表 temp(F4) 结果。是否可以对每一行进行while循环并且可以对更新进行排序？

谢谢！

Answer 1

假设ROW是一个正整数，那么你可以使用（演示）

WITH T1 AS
(
SELECT *, 
       MIN(CASE WHEN F4 <> 0 THEN CONCAT(FORMAT([ROW],'D10'),[F4]) END) 
         OVER (ORDER BY [ROW] ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS M
FROM temp

)
SELECT *, 
       CAST(SUBSTRING(M,11,11) AS INT) AS val
FROM T1
ORDER BY [ROW]

如果你想更新F4你可以使用

WITH T1 AS
(
SELECT *, 
      MIN(CASE WHEN F4 <> 0 THEN CONCAT(FORMAT([ROW],'D10'),[F4]) END) 
           OVER (ORDER BY [ROW] ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS M
FROM temp

)
UPDATE T1
SET F4 = COALESCE(SUBSTRING(M,11,11),0);