电子邮件地址的动态透视

Question

我已经尝试对此进行研究，但我无法找到类似的东西。我有一张表，其中可能多次添加和删除条目。我不知道我需要多少列，因此我需要一个动态枢轴。我看到的所有示例都使用 Windows 函数，但我正在旋转电子邮件地址。

表格看起来像这样：

Number | Email
--------------
1      | email1@email.com
1      | email2@email.com
1      | email3@email.com
2      | email4@email.com
2      | email5@email.com
3      | email6@email.com
4      | email7@email.com
4      | email8@email.com

我希望表格看起来像这样（当所有都包括在内时）：

Number | Email1           | Email2           | Email3           
---------------------------------------------------------------
1      | email1@email.com | email2@email.com | email3@email.com
2      | email4@email.com | email5@email.com |
3      | email6@email.com |                  |
4      | email7@email.com | email8@email.com |

如果不包括数字 1，它看起来像：

Number | Email1           | Email2                     
--------------------------------------------
2      | email4@email.com | email5@email.com 
3      | email6@email.com |
4      | email7@email.com | email8@email.com

感谢您的帮助！

这是创建模拟表的代码：

CREATE TABLE #table
(number INT, email VARCHAR(30))

INSERT INTO #table (number, email)
VALUES  (1,'email1@email.com')
       ,(1,'email2@email.com')
       ,(1,'email3@email.com')
       ,(2,'email4@email.com')
       ,(2,'email5@email.com')
       ,(3,'email6@email.com')
       ,(4,'email7@email.com')
       ,(4,'email8@email.com')

这与我尝试过的类似，我使用 count 尝试使其工作，但无法。

DECLARE @columns NVARCHAR(MAX), @sql NVARCHAR(MAX);
SET @columns = N'';
SELECT @columns += N', p.' + QUOTENAME(Number)
  FROM (SELECT p.Number FROM #table AS p
  GROUP BY p.Name) AS x;

SELECT @columns

SET @sql = N'
SELECT ' + STUFF(@columns, 1, 2, '') + '
FROM
(
  SELECT p.number, p.email
   FROM #test p
) AS j
PIVOT
(
  Count(email) FOR Name IN ('
  + STUFF(REPLACE(@columns, ', p.[', ',['), 1, 1, '')
  + ')
) AS p;';
PRINT @sql;
EXEC sp_executesql @sql;

Answer 1

您首先需要通过Number 上的分区创建RNO。 下面的查询应该做你想做的事：

CREATE TABLE #table (Number INT, Email VARCHAR(30))
INSERT INTO #table (Number, Email)
VALUES  (1,'email1@email.com')
       ,(1,'email2@email.com')
       ,(1,'email3@email.com')
       ,(2,'email4@email.com')
       ,(2,'email5@email.com')
       ,(3,'email6@email.com')
       ,(4,'email7@email.com')
       ,(4,'email8@email.com')

SELECT *, ROW_NUMBER() OVER (PARTITION BY Number ORDER BY Number, Email) AS [RNO] INTO #temp FROM #table

DECLARE @DynamicCols NVARCHAR(MAX) = '';
DECLARE @pvt NVARCHAR(MAX) = '';

SET @pvt = STUFF(
  (SELECT DISTINCT N', ' + QUOTENAME([RNO]) FROM #temp FOR XML PATH('')),1,2,N'')

SET @DynamicCols = STUFF(
  (SELECT DISTINCT N', ' + QUOTENAME([RNO]) + ' AS '+ QUOTENAME('Email' + CAST([RNO] AS VARCHAR(MAX))) FROM #temp FOR XML PATH('')),1,2,N'')


EXEC (N'SELECT [Number],'+ @DynamicCols+'
            FROM #temp tmp
        PIVOT (MAX([Email]) FOR RNO IN('+@pvt+')) AS PIV');