集團之間關鍵詞TSQL

Question

問題

我導入電子數據表，它包含在同一列作爲子父組數據。如下所示，我想爲組添加提取列。

創建表

DECLARE @Fruit TABLE 
    (
     ProductID INT IDENTITY(1, 1) 
        PRIMARY KEY , 
     FruitName NVARCHAR(20) , 
     FruitCost MONEY 
    ) 

INSERT INTO @fruit 
     (FruitName, FruitCost) 
VALUES ('Berry', NULL) 
INSERT INTO @fruit 
     (FruitName, FruitCost) 
VALUES ('BlueBerry', 2) 
INSERT INTO @fruit 
     (FruitName, FruitCost) 
VALUES ('StrawBerry', 2) 
INSERT INTO @fruit 
     (FruitName, FruitCost) 
VALUES ('Citrus', NULL) 
INSERT INTO @fruit 
     (FruitName, FruitCost) 
VALUES ('Lemon', 2) 
INSERT INTO @fruit 
     (FruitName, FruitCost) 
VALUES ('Orange', 2) 

SELECT * 
FROM @Fruit 

表結果

ProductID FruitName   FruitCost 
----------- -------------------- --------------------- 
1   Berry    NULL 
2   BlueBerry   2.00 
3   StrawBerry   2.00 
4   Citrus    NULL 
5   Lemon    2.00 
6   Orange    2.00 

需要的結果

FruitName   FruitCost    FruitGroup 
-------------------- --------------------- -------------------- 
BlueBerry   2.00     Berry 
StrawBerry   2.00     Berry 
Lemon    2.00     Citrus 
Orange    2.00     Citrus 

Answer 1

試試這個

select 
    f3.FruitName, f3.FruitCost, f.FruitName 
from 
    @Fruit f 
     inner join 
    (
     SELECT *, 
     (Select max(productid) from @Fruit f2 where FruitCost is null and ProductID<=f.ProductID) as fgroup 
     FROM @Fruit f 
    ) f3 
     on f.ProductID = f3.fgroup 
where f3.FruitCost is not null 

Answer 2

select t.FruitName,t.FruitCost, 
(select FruitName from @fruit t2 
    where t2.ProductId in 
    (
    select max(t3.ProductId) from 
    @fruit t3 
    where (t3.FruitCost is null) and (t3.ProductId<t.ProductId) 
    ) 

) FruitGroup 
from @Fruit t where (t.FruitCost is not null)