Question

我想填充序数列，但不想循环记录。有没有办法在单次更新中做到这一点？

CREATE TABLE #Sample
(PrimaryKey Int NOT NULL,
ParentKey Int NOT NULL,
Ordinal Int NULL)

INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (1, 1, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (2, 1, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (3, 1, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (4, 2, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (5, 2, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (6, 3, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (7, 4, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (8, 4, NULL)
INSERT #Sample (PrimaryKey, ParentKey, Ordinal) VALUES (9, 5, NULL)

SELECT * FROM #Sample
DROP TABLE #Sample

Ordinal列中的值为1,2,3,1,2,1,1,2,1 我想在每个小组中编号。由“ParentKey”和Ordinal定义的组应按“PrimaryKey”

排序

重要！不能依赖PrimaryKey和ParentKey中的值。他们有“漏洞”，没有必要增加1，如我的样本所示..

Answer 1

假设SQL Server 2005 +：

WITH CTE AS
(
    SELECT  *,
            RN = ROW_NUMBER() OVER(PARTITION BY ParentKey ORDER BY PrimaryKey )
    FROM #Sample
)
UPDATE CTE
SET Ordinal = RN

按顺序填充Ordinal列

1 个答案: