列中的调用历史 SQL SERVER

Question

我有一张桌子和

select [Caller ID] , [Call details] from [DEMO].[dbo].[calldetails]

想要多列的结果，如

Answer 1

您可以使用PIVOT 表运算符来执行此操作：

SELECT 
  [Caller ID],
  [1] AS [Call Details 1],
  [2] AS [Call Details 2],
  [3] AS [Call Details 3]
FROM
(
  SELECT 
    [Caller ID], 
    [Call details],
    ROW_NUMBER() OVER(PARTITION BY [Caller ID]
                      ORDER BY [Caller ID]) AS RN
  FROM [calldetails]
) AS t
PIVOT
(
   MAX([Call details])
   FOR RN IN([1], [2], [3])
) AS p;

请注意：

• 我使用基于Caller ID 生成的行号将通话详细信息分为 3 列。

• 我按Caller ID 排序结果，因为我必须使用ORDER BY 和PARTITION BY。这就是为什么您会发现结果的顺序与您要查找的顺序不同。

• SQL Fiddle Demo

这会给你：

| Caller ID |  Call Details 1 |  Call Details 2 | Call Details 3 |
|-----------|-----------------|-----------------|----------------|
|       123 | Ordered Product | Shipped Product |   More Details |
|       125 |  product search |          (null) |         (null) |
|       234 |  product search | Ordered Product |         (null) |

---

如果您想动态地执行此操作并且不手动列出这些行号列表，您必须像这样动态地执行此操作：

DECLARE @cols AS NVARCHAR(MAX);
DECLARE @colnames AS NVARCHAR(MAX);
DECLARE @query AS NVARCHAR(MAX);

SELECT @cols = STUFF((SELECT distinct ',' +
                        QUOTENAME(RN)
                       FROM 
               (
                 SELECT ROW_NUMBER() OVER(PARTITION BY [Caller ID] 
                                          ORDER BY [Caller ID]) AS RN
                 FROM [Calldetails] 
               ) AS t
                      FOR XML PATH(''), TYPE
                     ).value('.', 'NVARCHAR(MAX)') 
                        , 1, 1, '');

SELECT @colnames = STUFF((SELECT distinct ',' +
                        QUOTENAME(RN) + 'AS' +   
                        QUOTENAME('[Call details ' + CAST(RN AS NVARCHAR(5)) + ']')
                       FROM 
               (
                 SELECT ROW_NUMBER() OVER(PARTITION BY [Caller ID] 
                                          ORDER BY [Caller ID]) AS RN
                 FROM [Calldetails]
               ) AS t
                      FOR XML PATH(''), TYPE
                     ).value('.', 'NVARCHAR(MAX)') 
                        , 1, 1, '');

SELECT @query = 'SELECT [Caller ID], ' + @colnames +
                  ' FROM
                    (
                      SELECT
                        [Caller ID] , 
                        [Call details], 
                        ROW_NUMBER() OVER(PARTITION BY [Caller ID] 
                                          ORDER BY [Caller ID]) AS RN
                      FROM [calldetails]
                    ) AS t
                    PIVOT
                    (
                       MAX([Call details])
                       FOR RN IN(' + @cols + ')' +
                                      ') p';

execute(@query);

• SQL Fiddle Demo