Question

我的数据集结构如下：

ID  |  Feedback type  |  Feedback value
1      Overall rating    5 
1      Duration          23.5
1      Representative    Steve
2      Overall rating    4 
2      Duration          47
2      Representative    Jane

基本上，每组三行代表一次交互。我想要的是每个交互的一行，如下所示：

ID  |  Overall rating  |  Duration | Representative
1      5                  23.5       Steve
2      4                  47         Jane

我很难找到制作子查询的正确方法。在Excel中，我只是获取我的ID列表并在原始表中执行vlookup，但我不清楚如何在SQL中执行此操作。感谢您的任何指示！

Answer 1

这是理想的做法

SELECT *
FROM TableName
PIVOT(MAX([Feedback value])
      FOR [Feedback type] IN ([Overall rating], [Duration], [Representative])
     ) AS PVTTable

但是，用户无法使用pivot，因此也可以使用

SELECT [ID], 
       MAX(CASE WHEN [Feedback type] = 'Overall rating' 
                THEN [Feedback value] 
                ELSE '' END) AS 'Overall Rating',
       MAX(CASE WHEN [Feedback type] = 'Duration' 
                THEN [Feedback value] 
                ELSE '' END) AS 'Duration',
       MAX(CASE WHEN [Feedback type] = 'Representative' 
                THEN [Feedback value] 
                ELSE '' END) AS 'Representative'
FROM TableName
GROUP BY [ID]

Answer 2

我会采取不同的方式：

SELECT T0.ID, T0.[Overall Rating], T1.Duration, T2.Representative

FROM (SELECT ID, [Feedback Value] AS 'Overall Rating' where [Feedback Type] = 'Overall Rating' FROM TableName) T0

LEFT JOIN (SELECT ID, [Feedback Value] AS 'Duration' where [Feedback Type] = 'Duration' FROM TableName) T1 ON T0.id = T1.id

LEFT JOIN (SELECT ID, [Feedback Value] AS 'Representative' where [Feedback Type] = 'Representative' FROM TableName) T2 ON T0.id = T2.id

基本上，我正在创建＆＃34;子表＆＃34;查询 - 每个评级，持续时间和代表。因为它们都链接到相同的ID，所以您可以创建表格然后加入它们。当然，如果它是一个大型表，这不是创建此查询的最有效方法，但对于像您的示例那样小的东西，它应该可以正常工作。

SQL：将多行组合成一行，列数更多

2 个答案: