我需要按照Class, Color, Type
列中的组(SeqNo
)序列重新编号行:
Class | Color | Type | SeqNo
Animal | Brown | Terr | 1
Animal | Brown | Aqua | 3
Animal | White | Terr | 3
Plant | Green | Aqua | 2
Plant | Green | Aqua | 2
Plant | Green | Aqua | 2
Platn | Green | Terr | 9
为:
Class | Color | Type | SeqNo
Animal | Brown | Terr | 1
Animal | Brown | Aqua | 2
Animal | White | Terr | 1
Plant | Green | Aqua | 1
Plant | Green | Aqua | 1
Plant | Green | Aqua | 1
Plant | Green | Terr | 2
请问怎么做?
答案 0 :(得分:3)
您需要使用DENSE_RANK()
函数对序列进行编号,并使用CTE作为中间结果集。
INSERT INTO @t VALUES
('Animal', 'Brown', 'Terr', 1),
('Animal', 'Brown', 'Aqua', 3),
('Animal', 'White', 'Terr', 3),
('Plant', 'Green', 'Aqua', 2),
('Plant', 'Green', 'Aqua', 2),
('Plant', 'Green', 'Aqua', 2),
('Plant', 'Green', 'Terr', 9)
;WITH cte AS(
SELECT *, DENSE_RANK() OVER (PARTITION BY Class, Color ORDER BY Class, Color, Type) AS NewSeq
FROM @t
)
UPDATE t1
SET t1.SeqNo = t2.NewSeq
FROM @t AS t1
INNER JOIN cte AS t2 ON t1.Class = t2.Class AND t1.Color = t2.Color AND t1.Type = t2.Type
SELECT * FROM @t
输出:
Class Color Type SeqNo
Animal Brown Terr 2
Animal Brown Aqua 1
Animal White Terr 1
Plant Green Aqua 1
Plant Green Aqua 1
Plant Green Aqua 1
Plant Green Terr 2