sybase/sql 自连接多行

问题描述

您好 stackoverflow 社区，

Hi stackoverflow community,

如果第 1 列中的唯一 ID 相同，我将尝试进行自连接.

I'm trying to do a self join if the unique ID in Col 1 is the same.

表格代码:

CREATE TABLE #table (
  Unique_ID int, Product_code varchar(10)
)
INSERT INTO #table (Unique_ID, Product_code) VALUES (1111111111, 1)
INSERT INTO #table (Unique_ID, Product_code) VALUES (1111111111, 2)
INSERT INTO #table (Unique_ID, Product_code) VALUES (1111111111, 3)
INSERT INTO #table (Unique_ID, Product_code) VALUES (2222222222, 4)
INSERT INTO #table (Unique_ID, Product_code) VALUES (2222222222, 4)
INSERT INTO #table (Unique_ID, Product_code) VALUES (3333333333, 5)
INSERT INTO #table (Unique_ID, Product_code) VALUES (3333333333, 6)
INSERT INTO #table (Unique_ID, Product_code) VALUES (3333333333, 6)
INSERT INTO #table (Unique_ID, Product_code) VALUES (3333333333, 3)

#table 输入:

Unique_ID   Product_code
1111111111       1
1111111111       2
1111111111       3
2222222222       4
2222222222       4
3333333333       5
3333333333       6
3333333333       6
3333333333       3

所需的#table 输出:

Desired #table Output:

Unique_ID   Product_code  Product_code1  Product_code2  Product_code3
1111111111       1              2              3            (Null)
2222222222       4              4            (Null)         (Null)
3333333333       5              6              6               3

当前代码(不确定如何通过 Unique_ID 比较每一行):

Current code (Unsure how to compare each row by Unique_ID):

SELECT t1.Unique_ID, t1.Product_code, t2.Product_code AS [Product_code1]
FROM #temp AS t1
JOIN #temp AS t2 ON t1.Unique_ID = t2.Unique_ID
ORDER BY t1.Unique_ID

非常感谢任何提示和/或帮助

Any hints and/or help would be much appreciated thanks

推荐答案

试试这个.您需要一个中间步骤来通过相同的列关联不同的值:

Try this. You'll need an intermediate step to relate the different value through an identical column:

select *, seq=identity(int) into #temp from #table order by Unique_ID, Product_code
go

SELECT t1.Unique_ID, t1.Product_code as p1, t2.Product_code as p2, t3.Product_code as p3, t4.Product_code as p4
FROM #temp AS t1
LEFT JOIN #temp AS t2 ON t1.Unique_ID = t2.Unique_ID and t2.seq = t1.seq+1
LEFT JOIN #temp AS t3 ON t2.Unique_ID = t3.Unique_ID and t3.seq = t2.seq+1
LEFT JOIN #temp AS t4 ON t1.Unique_ID = t4.Unique_ID and t4.seq = t3.seq+1
where t1.seq = (select min(seq) from #temp where Unique_ID = t1.Unique_ID)
ORDER BY t1.Unique_ID
go

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