将 2 个结果记录转换为 1 个

Question

我需要取一张表的 2 行（总是 2 行）并将它们合并为 1 行，以便表中的这些字段：

烘烤时间、直径、尺寸、高度

最终变成这样的人

BakeTime1、BakeTime2、Diameter1、Diameter2、Size1、Size2、Height1、Height2

在最终结果记录中。表中有一个 'unique id' 字段，它是我想要一起输出的 2 条记录的唯一字段。

Answer 1

您应该能够使用内连接从两条记录生成单行。根据您在 cmets 中关于识别列 (CakeNo) 的陈述，类似下面的内容应该可以工作。

SELECT t1.BakeTime AS BakeTime1, t2.BakeTime as BakeTime2, t1.Diameter AS Diameter1, t2.Diameter AS Diameter2,
       t1.Size AS Size1, t2.Size AS Size2, t1.Height AS Height1, t2.Height AS Height2
FROM YourTable t1
INNER JOIN YourTable t2 ON t2.UniqueId = t1.UniqueId AND t2.CakeNo != t1.CakeNo
WHERE t1.UniqueId = 'YourIdHere' AND RIGHT(t1.CakeNo, 1) = 'A'

免责声明：我不完全确定我理解您对 CakeNo 的使用，LEFT(t1.CakeNo, 1) = '1' 可能需要代替 RIGHT(t1.CakeNo, 1) = 'A'。

Answer 2

;WITH cte AS (
    SELECT
       *
       ,LEFT(CakeNo,LEN(CakeNo) - 1) as CorrelationId
       ,ROW_NUMBER() OVER (PARTITION BY LEFT(CakeNo,LEN(CakeNo) - 1) ORDER BY CakeNo) as RowNum
    FROM
       TableName
)

SELECT
    c1.BakeTime as BakeTime1
    ,c2.BakeTime as BakeTime2
    ,c1.Diameter as Diameter1
    ,c2.Diameter as Diameter2
    ,c1.Size as Size1
    ,c2.Size as Size2
    ,c1.Height as Height1
    ,c2.Height as Height2
FROM
    cte c1
    INNER JOIN cte c2
    ON c1.CorrelationId = c2.CorrelationId
    AND c2.RowNum = 2
WHERE
    c1.RowNum = 1

根据您的评论，您可以从 CakeNo 的第一个字符中得出相关 ID。因为我假设您将拥有超过 9 条记录，所以我认为如果您从最后删除 A/B 就可以获得您的 CorrelationId。我已更新我的答案以反映这一点。

Answer 3

如果 ID 不同 - 从您的问题中不清楚

SELECT t1.*, t2.*   // yes you need to alias actual column names
FROM YourTable t1
JOIN YourTable t2 
      ON t1.UniqueId = 1   // id1
     AND t2.UniqueId = 2   // id2

如果 ID 相同而 CakeNo 不同
从马特（+1）那里借了很多东西

;WITH cte AS (
    SELECT *
         , ROW_NUMBER() OVER (PARTITION BY uniqueID ORDER BY CakeNo) as RowNum
    FROM
       TableName
  --where uniqueID = @ID -- in you only need one do it here  
)

SELECT
     c1.BakeTime as BakeTime1
    ,c2.BakeTime as BakeTime2
    ,c1.Diameter as Diameter1
    ,c2.Diameter as Diameter2
    ,c1.Size as Size1
    ,c2.Size as Size2
    ,c1.Height as Height1
    ,c2.Height as Height2
FROM
    cte c1
    left JOIN cte c2  -- in case only one row  
     ON c2.RowNum = 2
    AND c1.RowNum = 1

如果两个 CakeNo 相同，则此方法有效
如果超过两行具有相同的 ID 则只会得到前 2

Answer 4

由于您总是只有两行，请尝试这样的操作

SELECT Concat(Min(baketime), ',', Max(baketime)), 
       Concat(Min(diameter), ',', Max(diameter)), 
       Concat(Min(size), ',', Max(size)), 
       Concat(Min(height), ',', Max(height)) 
FROM   yourtable 

如果您使用的不是SQL Server 2012，则将CONCAT 替换为+ 运算符以连接字符串

更新：看起来你想要这个

SELECT Min(baketime), 
       Max(baketime), 
       Min(diameter), 
       Max(diameter), 
       Min(size), 
       Max(size), 
       Min(height), 
       Max(height) 
FROM   yourtable